Assertion (A): Detritus food chain may be connected with the grazing food chain at some levels.
Reason (R): Some of the organisms of detritus food chain are prey to the grazing food chain animals.

A and R are true and R is the correct explanation of A.

Assertion (A) is true; detritivores, which feed on dead organic matter in the detritus food chain, can be consumed by organisms in the grazing food chain. This connection occurs when predators in the grazing food chain feed on detritivores.

Reason (R) is also true and serves as an explanation for why the detritus food chain can be connected with the grazing food chain. Detritus food chains contribute to the overall energy flow and nutrient cycling in ecosystems, and their organisms can indeed serve as prey for consumers in other food chains.