A company could produce 99 units of a good for $316 or produce 100 units of the same good for $332. The $16 difference in costs is:

the marginal cost of producing the 101st unit.

neither the marginal benefit nor the marginal cost of producing the 101st unit.

the marginal cost of producing the 100th unit.

both the marginal benefit and the marginal cost of producing the 101st unit.