If n is a positive integer and n^2 is divisible by 72, then the largest positive integer that must divide n is  Choose the correct answer
A) 6 B) 12 C) 24 D) 36 E) 48

Rationale: "possible values of n = 12 , 24 , 36 and 48 . but it is 12 that can divide all the possible values of n . if we consider 48 , it will not divide 12 , 24 and 36 . hence , 12 is the value that must divide n . answer : b"
Answer: B