If a cost-minimizing firm sells its services in an oligopolistic market, with a marginal product of capital of 10, a rental rate of capital of $5, and a wage rate of $20, what is the marginal product of labor? 4 20 40 60 80

If a cost-minimizing firm sells its services in an oligopolistic market, with a marginal product of capital of 10, a rental rate of capital of $5, and a wage rate of $20, what is the marginal product of labor?

4
20
40
60
80