Which One of These Combinations Must Increase the Contribution Margin

Multiple Choice

Which one of these combinations must increase the contribution margin?

A) Increasing both the sales price and the variable cost per unit
B) Increasing the sales quantity and increasing the variable cost per unit
C) Decreasing the sales price and increasing the sales quantity
D) Decreasing both fixed costs and depreciation expense
E) Increasing the sales price and decreasing the variable cost per unit