Which of the following is true of the surface water and deep water of the ocean?(1 point A There is little vertical mixing between layers because currents only flow sideways.

B There is constant vertical mixing as fresh water evaporates and the salty surface water that remains sinks.

C There is constant vertical mixing between layers because the warm water is atop the colder water.

D There is little vertical mixing between layers because the warm water is atop the colder water.