A demand curve helps a firm examine prices in relation to what?

• A. Advertising
• B. Costs
• C. Inventory
• D. Demand

Answer: (D)

The main idea is how price relates to the quantity buyers are willing to purchase. A demand curve graphically shows the relationship between the price of a good and the quantity demanded by consumers, holding other factors constant. It illustrates the law of demand: as price falls, more people buy the good; as price rises, purchases fall. This helps a firm forecast how changing prices will affect sales and revenue. Advertising can influence demand by shifting the curve itself—more demand at every price—so it affects overall willingness to buy, but the curve’s core purpose is to map price to quantity demanded, not advertising costs. Costs relate to supply decisions, while inventory concerns stock levels, not the direct price–quantity relationship captured by demand.