Which of the following group of organisms are not constituents of a food chain?
(i) Grass, lion, rabbit, wolf
(ii) Plankton, man, fish, grasshopper
(iii) Wolf, grass, snake, tiger
(iv) Frog, snake, eagle, grass, grasshopper
Plankton, man, fish, grasshopper; Wolf, grass, snake, tiger are not group of food chain. Plankton and fish belong to aquatic food chain. Similarly, Wolf does not exist in a food chain with grass snake and tiger.