ANS:D - all of these.

1. Mechanized Receipt: The receipt of waste materials into the composting plant can be mechanized, involving the use of conveyor belts, loaders, or other mechanical equipment to transport and unload the incoming waste materials efficiently.
2. Mechanized Segregation: Once the waste materials are received, mechanized segregation processes can be employed to separate different types of waste streams based on their composition, size, or other characteristics. This segregation can help optimize the composting process and ensure that only suitable materials are processed further.
3. Mechanized Pulverizing of Refuse: Mechanized pulverizing or shredding of refuse is often a crucial step in the composting process. Mechanical equipment such as shredders or grinders can be used to break down the waste materials into smaller particles, which increases the surface area available for microbial action and accelerates the composting process.

Therefore, the correct answer is all of these. In a fully mechanized composting plant, mechanization is typically employed throughout the process, from receiving the waste materials to the final composting stages, to improve efficiency, consistency, and overall operational effectiveness.