Concept:The modal mark is the value that appears most frequently in the data set.Explanation:List the marks: 2,5,5,6,7,7,8,8,8,9,10.Count the frequency of each mark:2 appears 1 time, 5 appears 2 times, 6 appears 1 time, 7 appears 2 times, 8 appears 3 times, 9 appears 1 time, 10 appears 1 time.The mark 8 appears most often, with 3 occurrences.Answer:The modal mark is 8, which is option B.