Marginal cost ) is the change in total output from hiring one more factor of production.(b) is the change in total cost from producing one additional unit of output.(c) falls when there are diminishing returns.(d) is the change in the total cost when hiring one more factor of production.

(B) Is the change in total cost from producing one additional unit of output

Explanation:

Marginal cost is the change in the total cost of production as a result of increasing the quantity produced by one unit.

Diminishing returns causes marginal cost to increase.

Marginal product of labor (MPL) is the change in output as a result of hiring one more unit of labour.

the answer would be voluntary exchange -

"the act of buyers and sellers freely and willingly engaging in market transactions. moreover, transactions are made in such a way that both the buyer and the seller are better off after the exchange than before it occurred."

hope this : )

-shy