Final answer:
The Law of Demand states that as the price of a good or service increases, the quantity demanded will decrease, and vice versa, all else constant.
Step-by-step explanation:
The subject being discussed is Economics. Specifically, the question refers to the Law of Demand, which is a principle in economics that states that as the price of a good, service, or resource rises, the quantity demanded will decrease, and vice versa, all else constant.
For example, when the price of a gallon of gasoline increases, people tend to look for ways to reduce their consumption, such as combining errands or using alternative modes of transportation. This illustrates the inverse relationship between price and quantity demanded.
Economists use the Law of Demand to analyze consumer behavior and predict how changes in price will impact the quantity demanded of a product or service.