If accounting profit is greater than zero for a firm in a competitive industry, then which of the following must be true? Responses The firm has no fixed cost. The firm has no fixed cost. The firm has positive economic profit. The firm has positive economic profit. The firm's total revenue exceeds its explicit cost. The firm's total revenue exceeds its explicit cost. The firm's economic profit exceeds its opportunity cost. The firm's economic profit exceeds its opportunity cost. New firms will enter the industry in the long run