Index: lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/service/AssessmentServiceImpl.java
===================================================================
diff -u -r3310e8d45579c49d0261682c33ec7d24d0bc65dc -rc145f7087c6e9364a2886db4decbecb02b775ec9
--- lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/service/AssessmentServiceImpl.java	(.../AssessmentServiceImpl.java)	(revision 3310e8d45579c49d0261682c33ec7d24d0bc65dc)
+++ lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/service/AssessmentServiceImpl.java	(.../AssessmentServiceImpl.java)	(revision c145f7087c6e9364a2886db4decbecb02b775ec9)
@@ -848,20 +848,10 @@
 		    // refresh latest answers from DB
 		    QbOption qbOption = qbService.getOptionByUid(optionDto.getUid());
 		    optionDto.setName(qbOption.getName());
+		    boolean isAnswerAllocated = AssessmentEscapeUtils.isVSAnswerAllocated(qbOption.getName(),
+			    normalisedQuestionAnswer, isQuestionCaseSensitive);
 
-		    Collection<String> optionAnswers = AssessmentEscapeUtils.normaliseVSOption(optionDto.getName());
-		    boolean isAnswerMatchedCurrentOption = false;
-		    for (String optionAnswer : optionAnswers) {
-
-			// check is item unraveled
-			if (isQuestionCaseSensitive ? normalisedQuestionAnswer.equals(optionAnswer)
-				: normalisedQuestionAnswer.equalsIgnoreCase(optionAnswer)) {
-			    isAnswerMatchedCurrentOption = true;
-			    break;
-			}
-		    }
-
-		    if (isAnswerMatchedCurrentOption) {
+		    if (isAnswerAllocated) {
 			mark = optionDto.getMaxMark() * maxMark;
 			questionResult.setQbOption(qbOption);
 			break;
@@ -1433,18 +1423,13 @@
 		    continue;
 		}
 
-		boolean isAnswerAllocated = false;
-
 		String normalisedAnswer = AssessmentEscapeUtils.normaliseVSAnswer(answer);
+
+		boolean isAnswerAllocated = false;
 		for (QbOption option : qbQuestion.getQbOptions()) {
-		    Collection<String> alternatives = AssessmentEscapeUtils.normaliseVSOption(option.getName());
-		    for (String alternative : alternatives) {
-			if (isQuestionCaseSensitive ? normalisedAnswer.equals(alternative)
-				: normalisedAnswer.equalsIgnoreCase(alternative)) {
-			    isAnswerAllocated = true;
-			    break;
-			}
-		    }
+		    String name = option.getName();
+		    isAnswerAllocated = AssessmentEscapeUtils.isVSAnswerAllocated(name, normalisedAnswer,
+			    isQuestionCaseSensitive);
 		    if (isAnswerAllocated) {
 			break;
 		    }
@@ -1476,15 +1461,19 @@
 	AssessmentQuestion assessmentQuestion = assessmentQuestionDao.getByUid(questionUid);
 	QbQuestion qbQuestion = assessmentQuestion.getQbQuestion();
 	String normalisedAnswer = AssessmentEscapeUtils.normaliseVSAnswer(answer);
+	if (normalisedAnswer == null) {
+	    return null;
+	}
 
 	//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();
-		Collection<String> alternatives = AssessmentEscapeUtils.normaliseVSOption(name);
-		if (alternatives.contains(normalisedAnswer)) {
+		boolean isAnswerAllocated = AssessmentEscapeUtils.isVSAnswerAllocated(name, normalisedAnswer,
+			qbQuestion.isCaseSensitive());
+		if (isAnswerAllocated) {
 		    return option.getUid();
 		}
 		if (option.getUid().equals(targetOptionUid)) {
Index: lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/util/AssessmentEscapeUtils.java
===================================================================
diff -u -r3310e8d45579c49d0261682c33ec7d24d0bc65dc -rc145f7087c6e9364a2886db4decbecb02b775ec9
--- lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/util/AssessmentEscapeUtils.java	(.../AssessmentEscapeUtils.java)	(revision 3310e8d45579c49d0261682c33ec7d24d0bc65dc)
+++ lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/util/AssessmentEscapeUtils.java	(.../AssessmentEscapeUtils.java)	(revision c145f7087c6e9364a2886db4decbecb02b775ec9)
@@ -22,6 +22,7 @@
 
 package org.lamsfoundation.lams.tool.assessment.util;
 
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.stream.Collectors;
@@ -370,12 +371,21 @@
     }
 
     public static String normaliseVSAnswer(String answer) {
-	return answer == null ? null : answer.replaceAll(VSA_ANSWER_NORMALISE_JAVA_REG_EXP, "");
+	return StringUtils.isBlank(answer) ? null : answer.replaceAll(VSA_ANSWER_NORMALISE_JAVA_REG_EXP, "");
     }
 
     public static Set<String> normaliseVSOption(String option) {
-	return option == null ? Set.of()
-		: Stream.of(option.split(VSA_ANSWER_DELIMITER)).collect(Collectors
-			.mapping(answer -> AssessmentEscapeUtils.normaliseVSAnswer(answer), Collectors.toSet()));
+	return StringUtils.isBlank(option) ? Set.of()
+		: Stream.of(option.split(VSA_ANSWER_DELIMITER))
+			.collect(Collectors.mapping(answer -> AssessmentEscapeUtils.normaliseVSAnswer(answer),
+				Collectors.toCollection(LinkedHashSet::new)));
     }
+
+    public static boolean isVSAnswerAllocated(String option, String answer, boolean isCaseSensitive) {
+	if (StringUtils.isBlank(option) || StringUtils.isBlank(answer)) {
+	    return false;
+	}
+	return AssessmentEscapeUtils.normaliseVSOption(option).stream()
+		.anyMatch(s -> isCaseSensitive ? s.equals(answer) : s.equalsIgnoreCase(answer));
+    }
 }
\ No newline at end of file