Last year, Twins Company reported $750,000 in sales (25,000 units) and an operating income of $25,000. At the break-even point, the company's total contribution margin equals $500,000. Based on this information, which of the following statements is true?
A: The company's contribution margin ratio is 40%.
B: The company's break-even point is 24,000 units.
C: The company's variable expense per unit is $9.
D: The company's variable expenses are 60% of sales.