$25.$ Oatmeal is a normal good and cold cereal is a substitute for oatmeal. Raisins are a complement for oatmeal. Which of the following increases the demand for oatmeal?

A$)$ an increase in the price of raisins

B$)$ a decrease in income

C$)$ a decrease in population

D$)$ an increase in the price of cold cereal

$26)$ Which of the following shifts the demand curve for hot dogs leftward?

A$)$ an increase in the price of a hot dog bun

B$)$ a decrease in the price of a hot dog bun

C$)$ an increase in the price of a hot dog

D$)$ an increase in the price of a hamburger

$27.$ The observation that the demand curve for grape jelly shifts rightward every time the price of peanut butter falls means that grape jelly and peanut butter are

A$)$ complements.

B$)$ substitutes.

C$)$ inferior goods.

D$)$ normal goods.

$28.$ If the price of chicken falls, then in the market for beef

A$)$ the demand curve for beef shifts rightward.

B$)$ the demand curve for beef shifts leftward.

C$)$ there is a movement downward along the demand curve for beef.

D$)$ there is a movement upward along the demand curve for beef.