An analysis of domestic returns for the U.S. bond markets ranks fourth out of six countries. When the impact of exchange rates is considered, the U.S. is the lowest out of six. This means that the:

A. exchange rate effect for a U.S. investor who invested in foreign bonds was always negative (i.e. the U.S. dollar was weak)

B. exchange rate effect for a U.S. investor who invested in foreign bonds was always positive (i.e. the U.S. dollar was strong)

C. exchange rate effect for a U.S. investor who invested in foreign bonds was always positive (i.e. the U.S. dollar was weak)

D. exchange rate effect for a U.S. investor who invested in foreign bonds was always negative (i.e. the U.S. dollar was strong)