If n is a positive integer, which of the following expressions must be even?	Choose the correct choice from the following choices
A) (n − 1)( n + 7)	B) (n − 2)( n + 7)	C) (n − 2)( n + 10)	D) (n − 3)( n + 7)	E) (n − 3)( n + 11)
Whether n is even or odd, (n-2)(n+7) will have one odd factor and one even factor.   The product will be even.   The answer is (n − 2)( n + 7).
<result>B</result>
If n is a positive integer, which of the following expressions must be even?