A rm's current output level is (1:100 at which the firm's average total cost is $500. If the firm were to increase its production level to Q'=150, the firm's average total cost would be $4?5. Which of the following is true about the rm if it chooses to increase its level of production to (1'? a. The rm faces increasing returns b. The rm faces constant returns c. The rm faces diminishing returns d. The rm minimizes its ATC