The Price Level Is Measured in Some Time Period with an Index

The price level is measured in some time period with an index number,such as the number 118.6.How is such a number of use to us?

A) It allows us to compare it to the value of the same index number from another time period to determine the rate of change of the price level.
B) The index number tells us the rate of inflation.
C) It tells us the dollar value for the average basket of goods and services bought by the typical Canadian household.
D) It tells us the real value for the average basket of goods and services bought by the typical Canadian household.
E) It tells us the percentage change in the price level from the previous time period.