Which of the Following Statements Is TRUE

Multiple Choice

Which of the following statements is TRUE?

A) Marginal utility theory predicts that an increase in a consumer's income increases consumption of all goods.
B) It is possible to derive the law of demand-that a higher price decreases the quantity demanded-using marginal utility theory.
C) Marginal utility theory makes no prediction about a consumer's responses to hikes in the prices of the goods and services he or she consumes.
D) Marginal utility theory predicts that all goods are normal goods and that all goods are substitutes for each other.