Convection in the upper mantle magma injection at the spreading boundaries gravity pulling the plates downward at subduction zones these are three theorized causes of a) glacial melting. eliminate b) changing of the climate. c) high and low ocean tides. d) movement of the tectonic plates.

D)movement of the tectonic plates.

Explanation:

Lets understand first what convection is. It refers to the process through which denser material sinks and less dense material rises. This is because less dense material is more buoyant than denser one.

The earth is composed of water, rocks and air and all these things lower their density when there occurs an increase in their temperature.

So what happens when convection occurs in the upper mantle of earth, it raises the less dense material called magma  in uprising direction, because of the extreme heat in the Earth’s core. When molten lava moves upwards it moves in a fashion of convection, but then it cools down and sinks again.

As the earth surface is made up of tectonic plates. Scientists believe that when convection occur in mantle layer, it causes the movement of plates, This movement can be away from, or towards each other. The movement of tectonic plates causes shifts continents, ocean basins, earthquakes and pushes up mountains.

So D is best option.

Hope it helps!

the oceanic zone is typically defined as the area of the ocean lying beyond the continental shelf, but operationally is often referred to as beginning where the water depths drop to below 100 meters (328 feet), seaward from the coast to the open ocean.

explanation: