If n is an integer, which of the following…
To solve this question, we need to consider a few odd/even rules.
1) (even + even) or (odd + odd) = even
2) even + odd = odd
3) (even x even) or (even x odd) = even (Note that an even integer times any integer, whether even or odd, will yield an even answer for the product.)
4) odd x odd = odd
Doing a quick scan of our answer choices allows us to select C as the correct option. Regardless whether n is even or odd, 2 (which is even) times any integer will always be even.