Answer: 1) Price indexes, used to measure the rate of inflation
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Explanation:
CPI = consumer price index
The CPI is basically a value in which we use to see how the price of some certain goods are changing over time, which then helps us determine the average overall rate of inflation. Some inflation is good and it's actually encouraged (or sought after) but it's a good idea to keep that inflation in check. Deflationary pressure is a bad thing because it could lead to the economy shrinking, which means less output is made. In other words, if prices go down, then producers have less incentive to sell their goods/services, which puts downward pressure on economic output.
GDP deflator is a similar idea to the CPI, but it measures things in a different way. In all honesty, I'm not familiar with this term enough to explain it, but I'm sure you can probably find many resources elsewhere to help clear things up.
