C.)
We can substitute numbers for the variables to make them true. We'll have a=2, b=1, and c=-1. We see that 2(-1) > 1(-1) is false since -2 is not greater than -2, so B is incorrect. However, when we do 2(-1) < 1(-1), this is true since -2 is less than -1, so C is correct. Hope this helps!
:)
