Subduction of oceanic lithosphere at the trenches can act like a bulldozer to produce

Subduction of 'oceanic lithosphere' at the trenches can act like a 'bulldozer' to produce an accretionary wedge.

Explanation:

The action of subduction subsequently results in a gradual layering up of material on 'both sides of the plate'. This process of layering up of the material from the plates is called as accretion. When a lighter plate undergoes subduction, it not only subducts but also lifts up the other plate to a certain extent. This action directly results in the formation of an 'accretionary wedge'.

I'm pretty sure it's c. extremely gradual but not 100% sure though.