Profit for a perfectly competitive firm can be expressed as A. Profitequals (Upper P times Upper Q )minus (ATC times Upper Q )​, where P is​ price, Q is​ output, and ATC is average total cost. B. Profitequals Pminus ​ATC, where P is price and ATC is average total cost. C. Profitequals Pminus ​MC, where P is price and MC is marginal cost. D. Profitequals (Upper P minus TC )times Upper Q ​, where P is​ price, Q is​ output, and TC is total cost. E. Profitequals P times ​Q, where P is price and Q is output.