Question 472223
I could be true, because if m = n, we get 0 = 0.


II cannot be true. This is because the LHS is equal to m^2, and the RHS is equal to -m^2. They are equal only when m = 0.


III could be true. If m is some positive number (e.g. 5) we get an inequality such as 5 > -5, which is true.


Answer is D.