Which statement best describes the elasticity of demand?

The correct choice accurately describes elasticity of demand as the measure of how much the quantity demanded of a good or service responds to changes in its price. Specifically, elasticity quantifies this relationship, providing insight into the degree to which consumers will adjust their purchasing behavior according to price fluctuations. For instance, if a product's price increases and consumers significantly reduce their quantity demanded, this indicates high elasticity. Conversely, if quantity demanded remains relatively unchanged despite price changes, this suggests low elasticity.

Other options do not capture the essence of elasticity effectively. While consumer loyalty to brands is relevant to market behavior, it does not directly relate to the mathematical concept of elasticity. Additionally, elasticity considers both short-term and long-term responses of consumers, making it broader than just long-term habits. Lastly, while past buying trends might influence current demand, they do not define the elasticity of demand, which focuses more on immediate responses to price changes.