When output is less than the efficient level,

A) consumers are willing to pay more for another unit than it costs to produce the unit.
B) the amount consumers are willing to pay equals the cost of production.
C) the cost of production is greater than the price consumers are willing to pay.
D) the production costs can't be measured.
E) the marginal cost of producing the good must be greater than the marginal benefit from the good.

A