Figure 11-12 -Refer to Figure 11-12.Which of the Following Statements Is True

Figure 11-12
-Refer to Figure 11-12.Which of the following statements is true?

A) Da represents the long-run demand curve facing a monopolistic competitor in a constant-cost industry while Db depicts the demand curve in the short run.
B) Da represents the long-run demand curve facing a monopolistic competitor in a constant-cost industry while Db depicts the long-run demand curve in an increasing-cost industry.
C) Da represents the long-run demand curve facing a perfect competitor while Db depicts the long-run demand curve facing a monopolistic competitor.
D) Da represents the long-run supply curve in a perfectly competitive,constant-cost industry while Db depicts the long-run demand curve facing a monopolistic competitor in a decreasing-cost industry.