Zari takes a summer course in London, England. She doesn't buy British pounds at the U.S. airport, where the rate is 1 pound = $1.60. Upon arrival in London, she finds that she can buy pounds for $1.65 each. Which of the following is true?
A. Zari could have saved money by buying pounds at the U.S. airport.
B. Zari could have saved money by waiting to buy pounds in London.
C. The exchange rate for pounds increased during Zari's flight.
D. The exchange rate for pounds decreased during Zari's flight.
