An An is considered as a monopoly on cosmetic production with the following information: TR = 1000Q - 10Q2 and MC = 100 + 10Q If the firm determine the price as a monopolist, the selling price would be: Select one: O a. 500. O b. 600 O c. 700. O d. None of these answers. Suppose ABC is the only firm in the market producing product X. ABC has the demand function: P = 2,750 - 45*Q/8 and the total cost function: TC = (1/30)Q3- 15Q2+ 2,500Q. Determine the firm's marginal revenue function? Select one: O a. 2,750 - 90Q/4. O b. 2,750 - 450/4. O c. 2,750 - 45P/4. O d. None of these answers