Which of the following statements about profit is/are true?

A. Zero economic profits mean that the firm is not making any money (accounting profit equals zero).

B. When a firm earns normal profits, its economic profit is equal to zero.

C. Normal profit, by definition equals accounting profit.

D. When a firm earns a normal profit, its accounting profit is equal to its opportunity cost.

E. Normal profit, by definition is equal to a firm's opportunity cost.

F. The difference between economic profit and accounting profit is equal to OC.

G. When accounting profit is equal to OC, economic profit MUST be zero.