The marginal cost of producing the tenth unit is $4. The Option D.
Marginal cost refers to the additional cost incurred by producing one more unit of a product or providing one more unit of a service. This cost is usually used to make decisions regarding production levels and pricing strategies.
The formula for marginal cost is Change in cost / Change in quantity.
At 10 unit:
Cost 2 = 40, Cost 1 = $0.
Quantity 2 = 10, Quantity 1 = 0
The marginal cost of producing the tenth unit is:
= 40 - $0 / 10 - 0
= $40 / 10
= $4.
Hence, the marginal cost of producing the tenth unit is $4.