The correct option is A Cobra
The possible link 'A" that will feed on frog are not parrots as they are diet usually consists of berries, fruits, seeds, insects, and worms. Rabbits are herbivores, which means they eat only vegetables and plant-based foods. Even though wolf is a predator of frog, the wolf is not preyed upon by an eagle. So the correct link 'A' in the following food chain is the cobra.
So the correct order of the food chain is, Plant → insect → frog → "cobra" → Eagle.