Answer: The correct answer is-
Rabbit.
Food chain describes a linear path of energy transfer (in the form of organic matter) between different organisms present within an ecosystem.
The different organisms in the food chain occupy specific positions called trophic levels ( such as producers, primary consumers, secondary consumers, tertiary consumers, decomposers).
Primary consumers ( second trophic level of food chain) are the organisms that consume producers ( which occupy the first trophic level) for obtaining energy.
They are generally herbivores as they are dependent on plants (autototrophic organisms that synthesize their own food through photosynthesis).
Rabbits eat grass, various plants, and vegetables ( such as carrot), therefore it is a primary consumer.