Both X and Y are integers. In all cases where x is even, y is also even. Is xy even?

A- y - x is odd.

B- Sqrt of xy = 36


[spoiler]OA is D . The OE says that A is sufficient, even though the only way to satisfy A restriction is for Y to be even and x to be odd. How can the OE syas A is sufficient when the stem says that Both x and y must be positive ?????? There is no more explanation. [/spoiler]