What is the smallest integer k for which 64^k > 4^19?  Choose the correct choice from the following options.
A) 4 B) 5 C) 6 D) 7 E) 8

Rationale: 64 ^ k > 4 ^ 19 4 ^ ( 3 k ) > 4 ^ 19 3 k > 19 k = 7 the answer is d .
Answer: D