Answer:
I feel like all of them are wrong, but C. is the one that's closes to being right.
Explanation:
As you see, C is the closest to the answer.
x=1 y=2 z=3
So...
1+2=3
2-3=1
^
Is that right?
No, but that one is the only error, the other equations also have errors.
So if there's a button that says none of the above, pick that.
Hope this helped! :)