The marginal rate of substitution measures the

A) magnitude of the substitution effect.
B) total utility received by a consumer when equilibrium is achieved.
C) extra utility that a consumer derives from successive units of a product.
D) consumer's willingness to substitute one product for another so that total utility will remain constant.

Marginal Rate

Refers to the rate at which one quantity changes with respect to a change in another quantity, commonly used in the context of taxes and interest rates.

Substitution Effect

The change in consumption of goods in response to a change in their relative prices, holding the consumer's level of utility constant.

Total Utility

The total satisfaction or benefit that a person derives from consuming a certain quantity of goods or services.