k = 2^n + 6, where n is an integer greater than 1. If k is divisible by 9, which of the following MUST be divisible by 9?  Choose the correct choice from the following options.
A) 2^n - 8	B) 2^n - 2	C) 2^n-3	D) 2^n + 4	E) 2^n + 5
Given: k, M and N are integers   If k is a divisor of both N and M, then k is a divisor of N+M (and N–M and M–N)   We're told that 9 is a divisor of 2^n + 6   We also know that 9 is a divisor of9.   So, applying the abov erule, 9 is a divisor of 2^n + 6 +9, and 9 is a divisor of 2^n + 6 -9 =2^n-3   2^n-3
<result>C</result>
k = 2^n + 6, where n is an integer greater than 1. If k is divisible by 9, which of the following MUST be divisible by 9?