Calculating Contribution to Sales Ratio Steps:

• Compute contribution per unit: Selling price minus marginal (variable) cost = $40 -$22 = $18.
• Exclude fixed non-manufacturing overhead ($6) as it is not variable.
• Calculate ratio: ($18 /$40) × 100% = 45%. Why C is correct:
• Contribution to sales ratio is (contribution margin per unit / selling price per unit) × 100%, yielding 45%. Why the others are wrong:
• A: 25% incorrectly subtracts an arbitrary amount beyond variable costs.
• B: 30% wrongly includes fixed overhead in contribution: ($40 -$22 - $6) /$40 × 100%.
• D: 55% mistakenly uses marginal cost as contribution: $22 /$40 × 100%. Final answer: C