9.The more time people have to adjust to a price change,

A.the less elastic their demand will be.

B. will not affect the elasticity of their response, unless the good in question is a luxury good.

C.the more elastic their demand will be.

D.will not affect the elasticity of their response, unless the good in question is a necessity.

10.When a good has many close substitutes available, its demand is likely to be

A.less price elastic than for goods without close substitutes available.

B.more price elastic than for goods with many complementary goods available.

C.less price elastic than for goods with many complementary goods available.

D.more price elastic than for goods without close substitutes available.

11.Perfectly inelastic demand means that the

A.demand curve is perfectly vertical.

B.demand curve is perfectly horizontal.

C.price elasticity is exactly one.

D. response to a change in price is immediate.

12. Perfectly elastic demand means that

A.consumers are extremely (infinitely) sensitive to a change in price.

B.quantity demanded remains unchanged when the price changes by any amount, no matter how small.

C.the demand curve is perfectly vertical.

D.the elasticity of demand is one.