-The Above Figure Shows the Demand and Cost Curves for a Firm

-The above figure shows the demand and cost curves for a firm in monopolistic competition. The firm maximizes its profit by

A) producing 8 units at a price of $5 each.
B) producing 8 units at a price of $15 each.
C) producing 4 units at a price of $20 each.
D) producing 12 units at a price of $10 each.