When a peacock eats a snake, the snake eats insects, insects depend on green plants. Then peacock is at
A) Primary consumer
B) Primary decomposer
C) A final decomposer of plants
D) The apex of the food pyramid.

Hint: An ecosystem is a community of a variety of species that interacts and lives in the same physical environment. The ecosystem consists of food webs that depict the feeding relationships between organisms.

Complete answer:
Food Chains depicts the feeding relationships between organisms of the ecosystem. A simple food chain consists of producer and consumer {primary consumer (herbivore), the secondary consumer (carnivores), tertiary consumer (secondary consumer)}.In this food pyramid, green plants are always the base of the pyramid because they are producers as they can synthesize food. So, the green plants here are producers, insects depending on green plants are primary consumers, snake eating insects is a secondary consumer and the peacock is a tertiary consumer. The peacock is at the apex of the food pyramid.
Organisms that directly depend on the(green plants)producer are primary consumers.Primary decomposers break down the dead organisms into smaller compounds.Final decomposers of plants are organisms that release the nutrients into the soil to make them fertile.

Hence, the correct answer is option ‘D’.

Note:A food chain linear in fashion i.e. it has one producer and one or two consumers. Whereas the food web is the interconnection of these linear food chains. For example, A grasshopper eats grass, a frog eats a grasshopper, a snake eats a frog, a hawk eats a snake and is a food chain. A hawk might eat a mouse, a squirrel, or some other animal. The snake may eat a caterpillar or some other animal. And also for all the other animals in the food chain. These are several food chains interlinked to each other forming a food web.