An Increase in the Equilibrium Price of Japanese Yen Per

An increase in the equilibrium price of Japanese yen per dollar could be caused by a(n) :

A) increase in the general level of prices in Japan.
B) increase in the U.S. demand for domestically-built automobiles.
C) decrease in the U.S. income relative to the income in Japan.
D) increase in the supply of dollars on the foreign market.