Consider a Small Economy in Which Consumers Buy Only Two

Consider a small economy in which consumers buy only two goods -- apples and pears.In order to compute the consumer price index for this economy for two or more consecutive years,we assume that

A) the number of apples bought by the typical consumer is equal to the number of pears bought by the typical consumer in each year.
B) neither the number of apples bought by the typical consumer, nor the number of pears bought by the typical consumer, changes from year to year.
C) the percentage change in the price of applies is equal to the percentage change in the price of pears from year to year.
D) All of the above are correct.