Which of the Following Is True

Which of the following is true?

A) The objective of the firm is to maximize profits, by producing the amount that maximizes the difference between its total revenues and total cost.
B) The objective of the firm is to maximize profits, by producing the amount that maximizes the difference between its average revenue and average total cost.
C) The objective of the firm is to maximize profits, by producing the amount that maximizes the difference between its average revenue and average variable cost.
D) The objective of the firm is to maximize profits, by producing the amount that maximizes the difference between its marginal revenue and marginal cost.
E) None of the above is true.