One Reason the CPI Is Followed Very Closely by the Government,businesses,and

One reason the CPI is followed very closely by the government,businesses,and workers is that:

A) it indicates whether we are running a budget surplus or a deficit.
B) some wages,interest rates,tax rates,and government benefits are tied to changes in the value of the CPI.
C) it is the best measure of worker productivity in the service sector.
D) the gross national product is computed from the reported increases in the CPI.