Suppose We Examine How the Consumer's Optimum Changes When the Price

Suppose we examine how the consumer's optimum changes when the price of good X changes,while the consumer's tastes,income,and the price of all other goods are held constant.This procedure is used to derive

A) the Engel curve for good X.
B) the (ordinary) demand curve for good X.
C) the compensated demand curve for good X.
D) the substitution and income effects for good X.