The correct answer is option 'D' - Vegetable and fruit wastes.

Vermi composting is a process of composting organic waste using red worms (Eisenia fetida or Lumbricus rubellus). These red worms are commonly known as composting worms or red wigglers. They play a crucial role in breaking down the organic matter and converting it into nutrient-rich compost.

The red worms used in vermi composting need specific types of food to thrive and carry out their composting activities effectively. Here's why vegetable and fruit wastes are the correct answer:

1. Nutrient-rich: Vegetable and fruit wastes are rich in nutrients, such as carbohydrates, proteins, and vitamins. These nutrients are essential for the growth and development of the red worms.

2. Easy to consume: Red worms have a small mouth and no teeth. They rely on microorganisms, bacteria, fungi, and other decomposers to break down the organic matter into smaller particles. Vegetable and fruit wastes are relatively soft and easy to consume for the red worms.

3. Moisture content: Red worms require a moist environment to survive. Vegetable and fruit wastes typically have a high moisture content, which helps maintain the necessary moisture levels for the worms.

4. Balanced pH: Red worms prefer a slightly acidic to neutral pH range for optimal composting. Vegetable and fruit wastes, especially fruit peels and scraps, contribute to maintaining a balanced pH in the vermicomposting system.

5. Decomposition rate: Vegetable and fruit wastes decompose relatively quickly compared to other organic materials such as wood or paper. This ensures a continuous supply of food for the red worms and helps maintain an active composting process.

6. Odor control: Vegetable and fruit wastes, when properly managed in a vermicomposting system, tend to have less odor compared to other types of organic waste. This is important for indoor or small-scale vermicomposting setups.

In summary, red worms used in vermi composting require food that is nutrient-rich, easy to consume, has a balanced pH, decomposes quickly, and helps control odor. Vegetable and fruit wastes fulfill these requirements, making them the ideal food source for the red worms in a vermicomposting system.

Option a is correct answer