Final answer:
Option C.
At the Gakkel Ridge, the divergent movement of oceanic tectonic plates causes them to move away from each other, leading to the creation of new oceanic crust as molten rock rises to fill the space between them.
Step-by-step explanation:
The Gakkel Ridge, like other areas where oceanic tectonic plates are diverging, is experiencing plate motion that causes the plates to move away from each other.
This divergent movement is characteristic of rift zones, where upwelling currents in the mantle push apart the plates.
As a result, molten rock, or basaltic lava, rises from below to fill the gap, forming new oceanic crust.
This is distinct from a convergent boundary - where plates move towards each other, potentially leading to subduction - or a transform boundary, where plates slide past one another without creating or destroying crust.
Divergent boundaries are also places where convection currents in the mantle contribute to tectonic activity, resulting in the creation of new crust as the plates separate.
This process is balanced by the destruction of old crust at subduction zones, where one plate goes beneath another.
Specifically, at the Gakkel Ridge, divergent movement means that Earth's crust is being constructed, leading to the gradual widening of the ocean basin in that area.