Last year, a company reported $750,000 in sales (25,000 units) and a net 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 is true? Select one: a. The variable expenses are 60% of sales b. The break-even point is 24,000 units c. The variable expense per unit is $10 d. The contribution margin ration is 40%