What does the law of demand primarily explain?

The law of demand primarily explains the relationship between price and quantity demanded. It states that, all else being equal, as the price of a good or service decreases, the quantity demanded by consumers generally increases, and conversely, as the price increases, the quantity demanded typically decreases. This fundamental principle illustrates that price is a key factor influencing consumer purchasing behavior.

Understanding this relationship is crucial for businesses as it helps them predict how changes in pricing strategy could impact sales volumes. For example, if a company lowers the price of a product, the law of demand suggests that more consumers will likely purchase it, assuming demand is not affected by other factors.

The other options provided do not accurately capture the essence of the law of demand. The relationship between consumer income and demand is addressed by the concept of income elasticity of demand, while advertising and consumer preferences relate to different aspects of market behavior and psychology. These topics are important in understanding consumer behavior but are not the primary focus of the law of demand.