问题
单项选择题
The current annual inflation rate, as measured by using the Consumer Price Index (CPI), is best defined as:（）
A. increase in the CPI from a year ago.
B. percentage change in the CPI from its base period.
C. percentage change in the CPI from a year ago.
答案
参考答案：C
解析：
The inflation rate is the percentage change in the price index from a year earlier.