Correct Option: B. Rabbit Detailed Explanation: In a typical food web, organisms are classified based on their roles in the ecosystem, particularly in terms of how they obtain energy. The main categories are producers, primary consumers, secondary consumers, and tertiary consumers.

1. Producers: These are organisms that can produce their own food through photosynthesis or chemosynthesis. In this case, grass (Option A) is a producer because it uses sunlight to create energy through photosynthesis.
2. Primary Consumers: These are organisms that eat producers. They are typically herbivores, meaning they primarily consume plants. The rabbit (Option B) fits this category perfectly as it feeds on grass and other plant materials. Therefore, it is classified as a primary consumer.
3. Secondary Consumers: These organisms eat primary consumers. They can be carnivores (meat-eaters) or omnivores (eating both plants and animals). In this question, the fox (Option C) is a secondary consumer because it preys on rabbits and other small animals.
4. Tertiary Consumers: These are higher-level consumers that eat secondary consumers. The eagle (Option D) is an example of a tertiary consumer as it can prey on foxes and other animals.

Why Other Options Are Incorrect:

• A. Grass: This option is incorrect because grass is a producer, not a consumer. It does not consume other organisms for energy; instead, it produces its own food through photosynthesis.
• C. Fox: This option is incorrect because the fox is a secondary consumer. It relies on primary consumers like rabbits for its energy, rather than consuming producers directly.
• D. Eagle: This option is also incorrect as the eagle is a tertiary consumer. It preys on secondary consumers like foxes, making it higher up in the food chain than primary consumers.

Summary of Key Concepts:

• Producers (like grass) create their own food and form the base of the food web.
• Primary Consumers (like rabbits) eat producers and are the first level of consumers in the food web.
• Secondary Consumers (like foxes) eat primary consumers.
• Tertiary Consumers (like eagles) eat secondary consumers.

Revision Summary:

• Primary consumers are herbivores that eat producers (e.g., rabbits).
• Producers are organisms that generate energy through photosynthesis (e.g., grass).
• Secondary consumers eat primary consumers (e.g., foxes).
• Tertiary consumers eat secondary consumers (e.g., eagles).

Understanding these roles helps clarify the flow of energy in an ecosystem and the interdependence of organisms within a food web.