What Is One Practical Use by the Federal Government for the Consumer

What is one practical use by the federal government for the Consumer Price Index (CPI) ?

A) A decrease in CPI means that the government must cut salaries.
B) It helps determines the cost of living increases for Social Security recipients.
C) It helps determines whether to raise taxes.
D) It determines whether the government is paying too much for services.
E) An increase in CPI triggers an increase in the regulation of the largest private companies.