Final answer:
The subject in question relates to the law of demand in economics.
Step-by-step explanation:
The subject in question relates to the law of demand in economics. The law of demand refers to the inverse relationship between price and quantity demanded of a good or service.
When the price of a good or service increases, the quantity demanded decreases, and vice versa. This relationship is based on the assumption that all other variables affecting demand remain constant.
For example, when the price of gasoline increases, consumers may choose to reduce their consumption by carpooling or using public transportation, demonstrating the decrease in quantity demanded in response to higher prices.