Answer: The corrects answers are "C) the pressures of competition in the labor market" and A) will push wage rates toward the marginal revenue product of labor.".
Explanation: Because the correct and complete statement would be: Even when competitive companies cannot directly calculate the product of marginal income, the pressures of competition in the labor market will push wage rates towards the product of marginal income from labor.
Making it clear that the strong pressures that are the product of competition in the labor market pushed wage rates towards the product of marginal income.