Final answer:
The MRP of labor used to produce apples will likely double when the price of apples increases from $1 to $2 per pound in a competitive market, assuming demand, labor productivity, and other market conditions remain constant.
Step-by-step explanation:
When apple prices rise from $1 to $2 per pound, provided that the demand for apples remains unchanged and the market structure is competitive, the marginal revenue product (MRP) of labor used in producing apples is likely to change. The MRP is equivalent to the additional revenue a firm earns by employing one more unit of labor, defined as the marginal product of that labor (how many additional units of output the labor will produce) multiplied by the marginal revenue (the additional income from selling that output).
In a competitive market, firms are price takers and the price of the good is equal to the marginal revenue. Doubling the price of apples would, in theory, double the marginal revenue from selling apples. Therefore, if the marginal product of labor does not change, doubling the price will double the marginal revenue, and so double the MRP of labor, which supports option A. However, this assumes that labor productivity and other market conditions remain constant.
It's important to note that additional information might be needed to precisely determine the change in MRP, such as details about changes in labor productivity, production costs, or the elasticity of demand for apples. These factors could potentially affect the final calculation of changes in MRP.