Which of the Following Statements About Purchasing Power Parity Is

Which of the following statements about purchasing power parity is correct? PPP

A) is an index of the average value of exchange rates.
B) is a theory that says price levels in two countries should be equal when measured in a common currency.
C) allows for both countries' currencies to appreciate at their own rates of inflation.
D) will tend to cause those currencies with lower inflation rates to depreciate.
E) holds exactly in the short run but not in the long run.