Using the Notation P_t to Designate This Period's Price Level

Multiple Choice

Using the notation P_t to designate this period's price level and P_t-1 to designate last period's price level, the formula for measuring the inflation rate from last period to this period is

A) [(P_t - P_{t - 1}) / P_t] × 100.
B) [(P_{t -1} - P_t) / P_{t - 1}] × 100.
C) [(P_t - P_{t - 1}) / P_{t - 1}] × 100.
D) [(P_{t -1} - P_t) / P_t] × 100.