Decomposition in pools, ponds, and lakes takes place mostly in the zone.
a.
pelagic
b.
littoral
c.
benthic
d.
all of the above

The benthic layer is the layer which contains the majority of detritus feeders such as shrimp and worms therefore this is the layer that hold more of the decomposition in the pools ponds and lakes. This decomposing matter is the primary support of these animals in the layer and a vital part of the food chain.

Need the answers if its a multiple choice question