Final answer:
The law of diminishing marginal utility states that each additional unit of a good provides less satisfaction, leading consumers to purchase more only at lower prices, which corresponds with the law of demand.
Step-by-step explanation:
According to the law of diminishing marginal utility, individuals obtain less utility from additional units of a good. Therefore, they will buy larger quantities of a good only at lower prices, and this explains the law of demand. This concept is exemplified by the fact that the first unit of a good, like a T-shirt, provides more satisfaction (measured in utils) than subsequent units. As consumers experience diminishing additional satisfaction, they are only willing to purchase more if the price decreases, which aligns with the law of demand that states the quantity demanded of a good falls as the price rises, and vice versa.