Answer:
-6 is opposite of 6 it cannot be zero because that is not the opposite of anything I can't be 12 because the opposite of 6 is -6 and it can't be 6 because it would be the same number I hope this helps you out
0
Explanation:
-6 on a number line that is opposite is -6 then add 6 and you get 0
+ took the test
I think that it is c