In Order to Maximize Profits,firms Must Produce at the Lowest

In order to maximize profits,firms must produce at the lowest possible cost.However when producing at a cost that is higher than necessary:

A) a monopoly firm can continue to operate with lower profits but a competitive firm will have to exit the market.
B) a monopoly firm has the incentive to lower cost and increase profit but a competitive firm will increase price and remain in the market.
C) a monopoly firm will expand output and increase price while a competitive firm will not change output or price.
D) a monopoly firm has the incentive to produce at the lowest cost possible while a competitive firm will only earn a lower economic profit.