Final answer:
Wind is the factor that has the greatest impact on the vertical movement of deep ocean currents.
Step-by-step explanation:
The factor that has the greatest impact on the vertical movement of deep ocean currents is Wind. Wind exerts a force on the surface of the ocean, causing the surface waters to move. This movement then influences the deeper waters below, creating vertical currents. For example, strong winds blowing in a consistent direction can push surface waters towards one side, creating an upwelling of deeper waters on the opposite side.