Which of the following statements is not necessarily true when a competitive firm chooses its output level to maximise its profit in the short run? (Assume that marginal cost is not constant and is well defined at all levels of output.)

Group of answer choices

Total revenue is at least as great as total cost.

Marginal cost is at least as great as average variable cost.

Price is at least as great as average variable cost.

Price is equal to marginal cost.

Marginal cost is increasing.