Which of the following is true of ROI?

Which of the following is true of ROI?

A)  If Cost is $5 and Revenue is $5, your ROI is 0%
B)  If Cost is $5 and Revenue is $5, your ROI is 20%
C)  If Cost is $5 and Revenue is $5, your ROI is 50%
D)  If Cost is $5 and Revenue is $5, your ROI is 100%
E)  None of these answers are true of ROI

Answer: A