Suppose a company sells two products, products A and B. Product A's sales price is $20, variable costs are $12, and the units sold are 4,000. Meanwhile, Product B's sales price is $30, variable cost is $18, and units sold are 2,000. If operating income is $40,000, what are the company's total fixed costs? $16,000 $24,000 $36,000 $42,000