It is C because I can plot all those points and they are still on the blue line. If you don't believe me, plug them in to y=-3/2x+2, (-4,8 plugged in would look like this 8=-3/2(-4)+2 just plug the x and y coordinates in) and they will be correct.
In a compound interest equation, the first value is the initial investment. In this case, it would be 5000. After the 5000, you would enter the rate that is being used.