Which organism could occupy the position 'A' in the following food ch…

The correct answer is Option (3) → Snake

In a food chain each organism eats the one before it and is eaten by the one after it. Here the plant is the producer, the insect a herbivore and the frog a primary carnivore. Organism ‘A’ must eat frogs and must itself be eaten by the eagle, so it is a secondary carnivore.

Option (1) Rabbit — Incorrect. The rabbit is a herbivore. It feeds on plants, not on frogs, so it cannot follow the frog in this chain.

Option (2) Lion — Incorrect. The lion is a large top carnivore. It does not feed on frogs, and an eagle does not eat a lion.

Option (3) Snake — Correct. The snake feeds on frogs and is in turn caught by the eagle. It fits the place between the frog and the eagle.

Option (4) Sparrow — Incorrect. The sparrow feeds on seeds and insects, not on frogs, so it cannot come after the frog in this chain.

NCERT Extract:
Energy Flow – “You have read about the food chains and webs that exist in nature. Starting from the plants (or producers) food chains or rather webs are formed such that an animal feeds on a plant or on another animal and in turn is food for another. The chain or web is formed because of this interdependency.”
Energy Flow – “… The consumers that feed on these herbivores are carnivores, or more correctly primary carnivores (though secondary consumers). Those animals that depend on the primary carnivores for food are labelled secondary carnivores.”