Correct option is A
Given:
Marks of student A in subject S3 = 80
Marks of student B in subject S2 = 75
Formula Used:
Difference = Value 1 - Value 2
Solution:
From the table, retrieve the relevant scores:
Marks of A in S3 = 80
Marks of B in S2 = 75
Required difference = 80 - 75
Difference = 5
Final Answer
So the correct answer is (a)

