What factors cause the demand curve to shift?

• A. Supply-side factors such as input costs, production technology, taxes on producers, and the number of firms in the market.
• B. Changes in the price of the good itself, causing movements along the demand curve, seasonal variations, and short-term availability.
• C. Changes in consumer income, tastes/preferences, prices of related goods (substitutes and complements), expectations about the future, number of buyers (population), and government policies/advertising.
• D. Only changes in consumer tastes and advertising; other factors (like income or related goods' prices) only affect the quantity demanded, not the demand curve.

Answer: (C)