Which of the following is a determinant of demand?

Consumer preferences are a crucial determinant of demand because they directly influence the quantity of a good or service that consumers are willing and able to purchase at various price levels. When consumer preferences shift—whether due to changes in tastes, trends, or the availability of substitutes—the demand curve can shift to the right (increase in demand) or to the left (decrease in demand).

Understanding this concept is important because it highlights how factors external to the market, such as cultural shifts or marketing efforts, can significantly change consumer behavior. For example, if a new health study reveals the benefits of a certain food product, consumer preference for that product may increase, leading to higher demand even if prices remain unchanged.

The other factors listed do play important roles in the broader context of economic activity, but they either relate more directly to supply rather than demand or do not influence how much of a product consumers seek. Production costs are primarily a concern for suppliers in determining supply, the number of sellers affects market competition rather than individual consumer demand, and future production technology considerations are more relevant to supply-side adjustments than to current consumer preferences.