Answer:
C. One firm, a unique product, price control and entry barrier
Step-by-step explanation:
Monopolistic competition: This is a market structure in which there are many sellers selling differentiated product.
Differentiated product are products which differs in quality, brand name, styles.
Features of monopolistic competition
1. Many sellers and buyers
2. Existence of competitors
3. Sellers sell differentiated product
4. Limited price control.
Monopoly: This is a market structure characterized by a single seller selling a unique product in the market.
Features of Monopoly
1. There is a single seller and many buyers.
2. Seller sells a unique product.
3. There is entry barrier, that is, no free entry.
4. Presence of price control
5. Absence of competitors.