What factors can cause a shift in the demand curve for smartphones?

• A. A change in the price of smartphones, holding other factors constant
• B. Changes in production costs, technology, number of firms, and taxes on producers
• C. Changes in consumer incomes, tastes and preferences, prices of substitutes and complements, population/demographics, and expectations about future prices
• D. Government subsidies to producers, input prices, and technological advances in production

Answer: (C)