Under Perfect Competition,the Equilibrium Price of Labor Used to Produce

Under perfect competition,the equilibrium price of labor used to produce cloth will be equal to

A) the ratio of the marginal product of labor in the production of cloth to the marginal product of labor in the production of food times the ratio of the price of cloth to the price of food.
B) the marginal product of labor in the production of cloth times the price of cloth.
C) the price of cloth divided by the marginal product of labor in the production of cloth.
D) the average product of labor in the production of cloth times the price of cloth.
E) the slope of the production possibility frontier.