The Gulf Stream is a surface current in the Atlantic Ocean that flows northward from the Caribbean Sea and the Gulf of Mexico. It feeds another current that reaches northern Europe. Which of these events would cause the greatest changes to the path and strength of the Gulf Stream?

A. a strong earthquake that occurs on the floor of the Atlantic Ocean

B. an increase in the volume of river water that flows into the Gulf of Mexico

C. a reversal of direction in the prevailing winds over the Atlantic Ocean

D. a slight increase in the salinity of the Atlantic Ocean