Final answer:
The correct answer is D, indicating that there's an inverse relationship between price and quantity demanded as explained by the law of demand and illustrated by a downward sloping demand curve.
Step-by-step explanation:
The law of demand and the downward sloping demand curve tell us that there is an inverse relationship between price and quantity demanded. This means that as the price of a good or service increases, the quantity demanded decreases, and conversely, as the price decreases, the quantity demanded increases.
This relationship is graphically represented by a demand curve that slopes downward, such as in the provided demand schedule for gasoline.
In response to the multiple-choice question, the correct answer is D. There is an inverse relationship between price and quantity demanded.