If a Firm Is a Price Taker in Both the Input

If a firm is a price taker in both the input and output markets,its marginal revenue product of labor is given by

A) the price of its output times labor's marginal physical productivity.
B) the marginal value product of labor.
C) the marginal revenue product of capital times the ratio of the wage rate to the rental rate on capital.
D) all of the other answers are correct.