4. Suppose that a firm uses labor and capital to produce q units of output. When the price of labor and the price of capital increase by the same percentage, how will the firm change its combination of labor and capital to produce the same amount of output q?
(A) The firm will reduce the amount of labor and the amount of capital by the same percentage.
(B) The firm will increase the amount of labor and the amount of capital by the same percentage.
(C) The firm will use the same combination of labor and capital as they did before the prices change.
(D)The combination of labor and capital will depend on their marginal products.