If a and b are unique prime integers, which of the following must be even?
Options:
(A) ab
(B) a2b
(C) 2a2b
(D) 2ab
(E) ab^2 Think first, then make a decision. Some random thoughts:
Let's assume that a is an even prime integer and b is an odd prime integer, their subtraction results in an odd integer and an odd integer multiplied by an even integer yields an even integer. So the answer is (C).