The correct answer is option C, that is, a subduction zone.
Explanation:
A subduction zone gets produced when two plates collide with each other and one plate gets sinks underneath the other. For example, an oceanic plate can slope underneath the other oceanic plate, such as the formation of Indonesia, Japan, and the Aleutian Islands are the illustrations of this kind of subduction.
The oceanic ridge refers to the upliftment of the mountains because of the convection currents taking place underneath the ocean. The formation of the Rift valley takes place by the subsidence of landmass because of the activity of rift or fault. The deep-sea trench and the ocean basin refers to the depression in the surface of the Earth.
What forms when one oceanic plate is forced beneath another plate is C. a subduction zone. The name itself can explain it all - the prefix sub- in Latin means 'under,' and given that beneath and under mean the same, subduction zone is the answer you should pick. The other options do not show such a relationship which is why they are wrong.