If Ten Years Ago the Prices of the Items Bought

If ten years ago the prices of the items bought last month by the average consumer would have been much lower, then one can likely conclude that ________.

A) the aggregate price level has declined during this ten-year period
B) the average inflation rate for this ten-year period has been positive
C) the average rate of money growth for this ten-year period has been positive
D) the aggregate price level has risen during this ten-year period