If x+6 is an even integer, which one of the following must be an even integer?

A. x-3

B. 2x+5

C. 2x-5

D. 2x+6

D because for x+6 to be even, x must be even. So, a is incorrect because an even - an odd is not even and neither are b and c because of the same logic. However, when you multiply an even by a whole number, you get an even. And when you add an even number to that it is still even so D would be the answer.

D is the answer to this question