irms with market power determine the optimal price and quantity by Question 4Select one: a. equating MR with MC to find quantity, then setting the price that yields that quantity on the firm demand curve. b. adding the average fixed cost to the average total cost to find price, and producing the quantity that yields that price on the firm's demand curve. c. setting quantity at the point of minimum average total cost (ATC ), and setting price equal to that ATC times the concentration ratio. d. setting the price equal to the market price, and then equating that price with MC to find quantity