Which of the following processes has directly caused ocean currents to change over earths history
a. axial precession
b. continental drift
c. ice-albedo feedback
d. volcanic activity

Continental drift has directly changed ocean currents over earth’s history.

Explanation:

Plate tectonics is the process by which the continents drift about the planet Earth. This drifting will be usually two to three centimetres a year. When this happens over a million years, there will be significant change in size and position of land areas. This can explain about the climate changes on our planet. In earlier days of Earth history, the continental plates were locked together without moving. This changes gradually increased over time, expansion of land masses has affected the ocean currents. This will in turn affect the climate as the ocean currents involves the transfer of heat across the area.

The answer for your problem would be a. 7