Index: lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/dao/AssessmentResultDAO.java
===================================================================
diff -u -r36716004da333fcc5eb3f776801e3e5278719fd7 -r14f0555e4fe91e89ebaa9c9e7d29f0666e681437
--- lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/dao/AssessmentResultDAO.java	(.../AssessmentResultDAO.java)	(revision 36716004da333fcc5eb3f776801e3e5278719fd7)
+++ lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/dao/AssessmentResultDAO.java	(.../AssessmentResultDAO.java)	(revision 14f0555e4fe91e89ebaa9c9e7d29f0666e681437)
@@ -34,6 +34,8 @@
     List<AssessmentResult> getAssessmentResults(Long assessmentUid, Long userId);
 
     List<AssessmentResult> getAssessmentResultsByQbQuestion(Long qbQuestionUid);
+    
+    List<AssessmentResult> getAssessmentResultsByQbQuestionAndAnswer(Long qbQuestionUid, String answer);
 
     List<AssessmentResult> getAssessmentResultsBySession(Long sessionId, Long userId);
 
Index: lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/dao/hibernate/AssessmentResultDAOHibernate.java
===================================================================
diff -u -ra8614f8bb8ccde5d2068b34659649c3c93c4e0d1 -r14f0555e4fe91e89ebaa9c9e7d29f0666e681437
--- lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/dao/hibernate/AssessmentResultDAOHibernate.java	(.../AssessmentResultDAOHibernate.java)	(revision a8614f8bb8ccde5d2068b34659649c3c93c4e0d1)
+++ lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/dao/hibernate/AssessmentResultDAOHibernate.java	(.../AssessmentResultDAOHibernate.java)	(revision 14f0555e4fe91e89ebaa9c9e7d29f0666e681437)
@@ -27,6 +27,7 @@
 import java.util.Map;
 import java.util.TreeMap;
 
+import org.apache.commons.lang.StringUtils;
 import org.hibernate.query.NativeQuery;
 import org.hibernate.query.Query;
 import org.lamsfoundation.lams.dao.hibernate.LAMSBaseDAO;
@@ -142,13 +143,24 @@
 
     @Override
     public List<AssessmentResult> getAssessmentResultsByQbQuestion(Long qbQuestionUid) {
-	final String FIND_BY_QBQUESTION_AND_FINISHED = "SELECT r FROM  " + AssessmentQuestionResult.class.getName()
+	return getAssessmentResultsByQbQuestionAndAnswer(qbQuestionUid, null);
+    }
+
+    @Override
+    public List<AssessmentResult> getAssessmentResultsByQbQuestionAndAnswer(Long qbQuestionUid, String answer) {
+	String FIND_BY_QBQUESTION_AND_FINISHED = "SELECT r FROM  " + AssessmentQuestionResult.class.getName()
 		+ " AS q, " + AssessmentResult.class.getName() + " AS r "
-		+ " WHERE q.assessmentResult.uid = r.uid AND q.qbToolQuestion.qbQuestion.uid =:qbQuestionUid AND (r.finishDate != null) ORDER BY r.startDate ASC";
+		+ " WHERE q.assessmentResult.uid = r.uid AND q.qbToolQuestion.qbQuestion.uid =:qbQuestionUid AND (r.finishDate != null) ";
+	if (StringUtils.isNotBlank(answer)) {
+	    FIND_BY_QBQUESTION_AND_FINISHED += "AND TRIM(q.answer) = TRIM(:answer) ";
+	}
+	FIND_BY_QBQUESTION_AND_FINISHED += "ORDER BY r.startDate ASC";
 
 	Query<AssessmentResult> q = getSession().createQuery(FIND_BY_QBQUESTION_AND_FINISHED, AssessmentResult.class);
 	q.setParameter("qbQuestionUid", qbQuestionUid);
-//	q.addEntity("bq", AssessmentResult.class);
+	if (StringUtils.isNotBlank(answer)) {
+	    q.setParameter("answer", answer);
+	}
 	return q.list();
     }
 
Index: lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/service/AssessmentServiceImpl.java
===================================================================
diff -u -r952a9a9bb86760e4e827fb763008efb0aaaa54bc -r14f0555e4fe91e89ebaa9c9e7d29f0666e681437
--- lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/service/AssessmentServiceImpl.java	(.../AssessmentServiceImpl.java)	(revision 952a9a9bb86760e4e827fb763008efb0aaaa54bc)
+++ lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/service/AssessmentServiceImpl.java	(.../AssessmentServiceImpl.java)	(revision 14f0555e4fe91e89ebaa9c9e7d29f0666e681437)
@@ -1439,22 +1439,26 @@
 	//adding
 	if (previousOptionUid.equals(-1L)) {
 	    //search for duplicates and, if found, return false
+	    QbOption targetOption = null;
 	    for (QbOption option : qbQuestion.getQbOptions()) {
 		String name = option.getName();
 		String[] alternatives = name.split("\r\n");
 		if (Arrays.asList(alternatives).contains(answer)) {
 		    return Optional.of(option.getUid());
 		}
+		if (option.getUid().equals(targetOptionUid)) {
+		    targetOption = option;
+		}
 	    }
 
-	    for (QbOption targetOption : qbQuestion.getQbOptions()) {
-		if (targetOption.getUid().equals(targetOptionUid)) {
-		    String name = targetOption.getName();
-		    name += "\r\n" + answer;
-		    targetOption.setName(name);
-		    assessmentDao.saveObject(targetOption);
-		    break;
-		}
+	    String name = targetOption.getName();
+	    name += "\r\n" + answer;
+	    targetOption.setName(name);
+	    assessmentDao.saveObject(targetOption);
+
+	    if (log.isDebugEnabled()) {
+		log.debug("Adding answer \"" + answer + "\" to option " + targetOptionUid + " in question "
+			+ questionUid);
 	    }
 
 	}
@@ -1465,10 +1469,10 @@
 		    String name = previousOption.getName();
 		    String[] alternatives = name.split("\r\n");
 
-		    String nameWithoutUserAnswer = "";
+		    StringBuilder nameWithoutUserAnswer = new StringBuilder();
 		    for (String alternative : alternatives) {
 			if (!alternative.equals(answer)) {
-			    nameWithoutUserAnswer += alternative + "\r\n";
+			    nameWithoutUserAnswer.append(alternative).append("\r\n");
 			}
 		    }
 		    if (nameWithoutUserAnswer.length() > 2) {
@@ -1501,30 +1505,28 @@
 		    String name = previousOption.getName();
 		    String[] alternatives = name.split("\r\n");
 
-		    String nameWithoutUserAnswer = "";
+		    StringBuilder nameWithoutUserAnswer = new StringBuilder();
 		    for (String alternative : alternatives) {
 			if (!alternative.equals(answer)) {
-			    nameWithoutUserAnswer += alternative + "\r\n";
+			    nameWithoutUserAnswer.append(alternative).append("\r\n");
 			}
 		    }
-		    if (nameWithoutUserAnswer.length() > 2) {
-			nameWithoutUserAnswer = nameWithoutUserAnswer.substring(0, nameWithoutUserAnswer.length() - 2);
-		    }
-		    previousOption.setName(nameWithoutUserAnswer);
+		    previousOption.setName(nameWithoutUserAnswer.length() > 2
+			    ? nameWithoutUserAnswer.substring(0, nameWithoutUserAnswer.length() - 2)
+			    : "");
 		    assessmentDao.saveObject(previousOption);
 		    break;
 		}
 	    }
 	}
-	assessmentResultDao.flush();
+	assessmentDao.flush();
 
 	//recalculate marks for all lessons in all cases except for reshuffling inside the same container
 	if (!targetOptionUid.equals(previousOptionUid)) {
 
 	    // get all finished user results
 	    List<AssessmentResult> assessmentResults = assessmentResultDao
-		    .getAssessmentResultsByQbQuestion(qbQuestion.getUid());
-
+		    .getAssessmentResultsByQbQuestionAndAnswer(qbQuestion.getUid(), answer);
 	    //stores userId->lastFinishedAssessmentResult
 	    Map<Long, AssessmentResult> lastFinishedAssessmentResults = new LinkedHashMap<>();
 	    for (AssessmentResult assessmentResult : assessmentResults) {