Which of the following is correct?
a. The GDP deflator is better than the CPI at reflecting the goods and services bought by consumers.
b. The CPI is better than the GDP deflator at reflecting the goods and services bought by consumers.
c. The GDP deflator and the CPI are equally good at reflecting the goods and services bought by consumers.
d. The GDP deflator is more commonly used as a gauge of inflation than the CPI is.