Answer:
Eagle is the top carnivore of grazing chain. It usually starts from producers, then insects, then small birds, then an eagle.
An earthworm has been identified as the chief component of the detritus food chain.
A frog is identified as a secondary consumer which feeds on a primary consumer forming a part of the grazing food chain.
So, the correct option is 'A-Top carnivore, B-Detritus, C-Secondary consumer'.
