If the integer n has exactly four positive divisors, including 1 and n, how many positive divisors does n^2 have?  Choose the correct choice.
A) 4 B) 5 C) 6 D) 8 E) 9
take the example of 6...   it has 4 positive divisors (1,2,3,4)   Now, take the example of 36...   it has only 9 divisors..   so 9 is the ans
<result>E</result>
If the integer n has exactly four positive divisors, including 1 and n, how many positive divisors does n^2 have?