A consumer's demand curve for a product is downsloping because

A) total utility falls below marginal utility as more of a product is consumed.
B) marginal utility diminishes as more of a product is consumed.
C) time becomes less valuable as more of a product is consumed.
D) the income and substitution effects precisely offset each other.

Marginal Utility

The additional satisfaction or usefulness gained from consuming one more unit of a good or service.

Income Effect

is the change in an individual's or economy's income and how that change will impact the quantity demanded of a good or service.

Substitution Effect

The change in consumption patterns due to a change in relative prices, leading consumers to replace more expensive items with less expensive ones.