Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

A profit maximum is least likely to occur when:
Option A:average total cost is minimized.
Option B:marginal revenue equals marginal cost.
Option C:the difference between total revenue and total cost is maximized.

Answer: A