Correct option is B
Given:
Total students = 9
4 students failed (i.e., scored < 40%)
The remaining 5 students passed with scores: 80%, 55%, 52%, 66%, 81%
Solution:
Let’s denote failed students with marks < 40%, say: F1, F2, F3, F4
Arrange the 5 known values:
52%, 55%, 66%, 80%, 81%
Merge into one ordered list of 9 values:
Since F1 – F4 < 40%, they will be placed before 52%.
So full ordered list:
F1, F2, F3, F4, 52, 55, 66, 80, 81
The 5th value = 52%
The median of the percentage marks is 52%.

