If positive integers x and y are not both odd, which of the following must be even?	Choose the correct choice:
A) xy
B) x + y
C) x - y
D) x + y -1
E) 2(x + y) - 1
Positive integers x and y are NOT both odd, means that either both x and y are even or one is even and the other one is odd. In either case xy must be even.   xynswer: xy.
<result>A</result>
If positive integers x and y are not both odd, which of the following must be even?