Suppose There Are Only Two Countries in the World, Mexico

Suppose there are only two countries in the world, Mexico and the United States. In the foreign exchange market, it follows that the

A) demand for pesos is linked to the demand for dollars.
B) demand for pesos is linked to the supply of pesos.
C) supply of pesos is linked to the demand for dollars
D) supply of pesos is linked to the supply of dollars.