In order to sell more of its product, a monopolist must:

• A. lower the price of its product
• B. raise barriers to entry
• C. keep the price unchanged
• D. increase the price of its product

Answer: (A)

Verified step by step guidance

1. Understand the basic principle of a monopolist's demand curve: since the monopolist is the sole seller, the demand curve it faces is the market demand curve, which is typically downward sloping.
2. Recognize that to sell more units, the monopolist must move along the demand curve to a higher quantity demanded, which usually requires lowering the price because of the inverse relationship between price and quantity demanded.
3. Recall that raising barriers to entry affects potential competitors but does not directly influence the quantity sold in the short run; it is a long-term strategic action rather than a method to increase current sales volume.
4. Note that keeping the price unchanged will not increase the quantity sold because the quantity demanded at that price remains the same according to the demand curve.
5. Understand that increasing the price of the product will typically reduce the quantity demanded, so it is not a method to sell more units.