What Is the Weighted Average Contribution Margin (WACM) Per Unit

What is the weighted average contribution margin (WACM) per unit?

A) The difference between a company's fixed costs and variable costs, expressed as a per unit amount based on units sole.
B) The measurement of a company's direct operating leverage, expressed as a per unit amount based on units sold.
C) The sum of the unit contribution margin for each product multiplied by its respective sales mix percentage.
D) The difference between a company's net sales revenues and net income, divided by total sales units.