Explanation:

- Marginal utility curve: Represents the additional satisfaction (utility) a consumer gets from consuming one more unit of a good. It's typically downward sloping, showing diminishing marginal utility.

- Indifference curve: Shows combinations of two goods that give the consumer the same level of satisfaction. Not related to marginal utility directly.

- Total utility curve: Represents the total satisfaction a consumer receives from consuming a given quantity of a good. This is cumulative, unlike the marginal utility.

- Supply curve: Shows the relationship between the price of a good and the quantity supplied. It's related to producers, not consumers.

- Demand curve: Illustrates the relationship between the price of a good and the quantity demanded by consumers. It often resembles the marginal utility curve because both demonstrate how consumption changes with price or utility.

Demand curve is the correct answer.