Ans. (d) The littoral zone is the zone at the edge of a lake or ocean or in an aquatic habitat which is alternatively exposed to air, hence, light is also available and immersed in water.

This coastal zone is rich producers from the surface to bottom, with a large number of brown and red alga attached at the zone. Different zona is an aquatic ecosystem.

Pelagic zone Any zone of water in a sea or lake that is neither close to the bottom nor the shore is a pelagic zone.

Benthic zone It is the bottom part of the water body (aphotic zone) light is not available here and it is dark. microorganisms and benthic organisms are found in this zone.

Lentic zone refers to standing or relatively still water in an equatie ecosystem.