The value of money is affected by the inflation rate-the higher the inflation
rate, the less valuable money will become over time. The rate of inflation is
calculated using the formula below, in which CPI represents the consumer price
index, a measure of the average of a typical basket of consumer goods and
services (where goods and services are weighted relative to how often they are
purchased by a normal consumer): \(\frac{\text { This Year's CPI - Last Year's
CPI }}{\text { Last Year's CPI }} \times 100\) The current rate of inflation
would definitely be zero if the CPI a year ago equaled which of the following?
(A) The CPI a year from now
(B) This year's CPI
(C) Zero
(D) 100