Along a Given Indifference Curve, a Consumer Reduces the Quantity

Multiple Choice

Along a given indifference curve, a consumer reduces the quantity of one good in favor of more units of the other. In this situation

A) the marginal rate of substitution falls.
B) the marginal utility of the first rises and the marginal utility of the second good falls.
C) total utility rises.
D) both A and B are correct.