If m is a positive integer and m^2 is divisible by 39, then the largest positive integer that must divide m is?	Choose one:
A) 3 B) 6 C) 8 D) 12 E) 13

Rationale: "m ^ 2 is divisible by 48 so m ^ 2 must be multiple of 48 . if the value of m is multiples of 13 then it will satisfy the condition . if we if m is 12 or 24 or 36 then it ans is e but if m = 39 then answer should be 16 . is the question right ? or am i missing some thing ? e"
Answer: E