If 7^k = 2, then 7^(4k+2) =
Choose the correct choice from the following answers:  A) 729  B) 754  C) 784  D) 783  E) 108

Rationale: "7 ^ k = 2 7 ^ 4 k = 2 ^ 4 7 ^ 4 k = 16 7 ^ ( 4 k + 2 ) = 7 ^ 4 k * 7 ^ 2 = 16 * 49 = 784 answer : c"
Answer: C