I think the answer is A. If you use the values for each variable approximately a(2.2) or b(8.5) or c(3.7). You will find that the only way to get a number greater than the value of "a" is to have a value that is fairly high. Thus, if you substitute my values into the equation you will see that the answer is greater than "a". Hope this helped :))
4x + y = 1
-2x - y = -8
2x = -7
x = -7/2
2(-7/2) + y = 8
-7 + y = 8
y= 15
elimination