Answer:
The correct answer is option A.
Step-by-step explanation:
Marginal cost is the cost of producing an additional unit of output. It is the increase in the total cost when an additional unit of output is produced.
The marginal cost curve is a U shaped curve. Initially, the marginal product of labor is rising, so the marginal cost will be decreasing. But after reaching a certain maximum point, the marginal product of labor starts declining. At the same time, the marginal cost of production will start rising.