For a Given Year, an Index Number of Average Prices

For a given year, an index number of average prices (such as the Consumer Price Index) is the ratio of the

A) price of several goods in the given year to that in the base year.
B) average price of several goods in the base year to that in the given year.
C) average price of all goods in the given year to that in the base year.
D) weighted prices of a typical bundle of goods purchased in a given year to that in the base year.
E) weighted prices of a typical bundle of goods purchased in the base year to that in the given year.