What is the smallest integer k for which 64^k > 4^16?
Choose the correct choice from the following answers:
A) 4  B) 5  C) 6  D) 7  E) 8

Rationale: "64 ^ k > 4 ^ 16 4 ^ ( 3 k ) > 4 ^ 16 3 k > 16 k = 6 the answer is c ."
Answer: C