Whenever the marginal product of a firm's only variable input was positive, but falling:

Question

Quizplus · Accepted Answer

The fact that the marginal product is positive but falling means that the total product is still increasing, but at a decreasing rate. Therefore, choice A is the correct answer. Choice B is incorrect because the firm would not continue to use more of the variable input until the marginal product is negative since that would lead to a decrease in total product, which contradicts the premise that the marginal product is still positive. Choice C is also incorrect for the same reason. Choice D is incorrect because if the total product were beyond its maximum, then the marginal product would be zero, not positive but falling.

Whenever the Marginal Product of a Firm's Only Variable Input