Contribution margin is selling price minus variable cost per unit

Steps:

• Recall contribution to sales (margin) formula: selling price per unit minus variable cost per unit.
• Note fixed costs and profit are irrelevant to this per-unit calculation.
• Check each option for ability to compute the formula's components.
• Confirm A lacks a required input, while others allow derivation.

Why A is correct:

• Variable cost per unit is absent, preventing subtraction from selling price per the contribution margin formula.

Why the others are wrong:

• B: Provides selling price and variable cost directly for the calculation.
• C: Includes selling price and variable cost (fixed cost extra but irrelevant).
• D: Contribution equals profit per unit plus fixed cost per unit, derivable without selling price.

Final answer: A