Answer:
C. none of the above
Step-by-step explanation:
A. x - (- x) is the equivalent of x + x, because subtracting a negative number is the same as adding it's positive counterpart. Therefore, it will be 2x, not -x.
B. Same thing. But this time, 0 - (- x) is the same as 0 + x, which is x, not -x.
Because neither are right, the only answer is C.
