The Figure Given Below Shows the Cost and Revenue Curves

The figure given below shows the cost and revenue curves of a monopolist.Figure 11.9
D: Average revenue
MR: Marginal revenue
ATC: Average total cost
MC: Marginal cost
-If a monopolistically competitive industry is in long-run equilibrium and suddenly the cost of resources increases, then:

A) the demand and average-revenue curves will shift to the right.
B) the demand and average-revenue curves will shift to the left.
C) some firms will eventually leave the industry.
D) new firms will eventually enter the industry.
E) the cost structure of the firm will shift down.