9. A 5 percent increase in the Consumer Price Index (CPI) means a

A) 5 percent increase in the cost of living.

B) less than 5 percent increase in the cost of living because consumers substitute cheaper products for those whose prices rise.

C) more than 5 percent increase in the cost of living because consumers substitute cheaper products for those whose prices rise.

D) less than 5 percent increase in the cost of living because of falling quality of products over time.

E) more than 5 percent increase in the cost of living because of the introduction of new products.