15. The firm shown in the figure above i..-阿摩線上測驗
15. The firm shown in the figure above is _______.
(A) not a natural monopoly because its MC curve is below its ATC curve.
(B) not a natural monopoly because its MC curve is horizontal.
(C) not a natural monopoly because its ATC curve slopes downward where it intersects the demand curve.
(D) a natural monopoly because its ATC curve slopes downward where it intersects the demand curve.