Using the Notation P_t to Designate This Periodʹs Price Level

Multiple Choice

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

A) [P_t-1 - P_t) / P_t] × 100.
B) [P_t - P_t-1) / P_t] × 100.
C) [P_t - P_t-1) / P_t-1] × 100.
D) [P_t-1 - P_t) / P_t-1] × 100.