The answer is a. because the first thing i did was had X as zero. it worked for all of them.
so i tryed -4 as X and Y as zero and it got rid of D and B.
so i tryed -2 as X and Y as 1. and it worked.
1= 0.5(-2) + 2 is correct.
-2 + 2 is not equal to 1 this = to 0
and
-2(-2)+2 is not equal to 1 ether. this = to 6