The correct option is A Detritivores.
Benthos is the community of organisms which live on, in, or near the seabed, also known as the benthic zone. Because light does not penetrate very deep ocean-water, the energy source for deep benthic ecosystems is often organic matter from higher up in the water column which drifts down to the depths. This dead and decaying matter sustains the benthic food chain; most organisms in the benthic zone are scavengers or detritivores.