Which of the Following Are Inversely Related to Variable Costs

Multiple Choice

Which of the following are inversely related to variable costs per unit?
I.contribution margin per unit
II.number of units sold
III.operating cash flow per unit
IV.net profit per unit

A) I and II only
B) III and IV only
C) II, III, and IV only
D) I, III, and IV only
E) I, II, III, and IV