Contribution to Sales Ratio Calculation Steps:

• Determine sales per unit: 750,000 / 375 = 2,000; confirm with 1,000,000 / 500 = 2,000.
• Calculate contribution per unit: (250,000 - 100,000) / (500 - 375) = 150,000 / 125 = 1,200.
• Compute ratio: (1,200 contribution per unit / 2,000 sales per unit) × 100% = 60%.
• Verify using total change: (150,000 change in profit / 250,000 change in sales) × 100% = 60%.

Why C is correct:

• Contribution to sales ratio equals (change in contribution / change in sales) × 100%, and since change in contribution equals change in profit, it is 150,000 / 250,000 = 60%.

Why the others are wrong:

• A. 25%: Matches neither profit margin (13%–25%) nor any valid cost proportion.
• B. 50%: Incorrect midpoint; actual ratio is derived from marginal changes, not halved.
• D. 83%: Possible error like (total contribution + fixed costs misapplied)/sales, but exceeds true 60%.

Final answer: C