Ridge push involves
gravity causing the plate to slide away from the topographically high ridge, pushing the plate outward.
gravity causing the plate to slide toward the topographically high ridge, pulling the plate inward.
gravity causing the plate to slide sideways to the topographically high ridge, pushing the plate into the rift between the two plates.

Gravity causing the plates to slide away  and pushing the plates outward.

Explanation:

It is a sliding plate force that drives the plates toward the mid-oceanic ridges and thus pushing it outwards,  as a result of the rigid lithosphere sliding down the hot asthenosphere.  The mechanism is a result of gravitational force acting on the younger plate by raising the lithosphere and mid-oceanic ridges. This ridge is a divergent boundary that makes or forms new plates and the rising of the magma occurs here. Forming a relatively shallow depth of 60 kilometers long tench, earlier models propounded by the harry Hess as seafloor spreading. Naming this zone as a Subduction zone. According to Stefanick and Jurdy, the slab push force acting in southern America is 5 times the slab pull in subduction margins due to the size of the Caribbean margin slabs.

Avertical or horizontal line used in graphs is called a(n) equatorhope this