Which plumbing fixture serves the dual purpose of collecting and discharging waste materials?

The correct answer, which is the receptor, serves the dual purpose of collecting and discharging waste materials. In plumbing terms, a receptor typically refers to a fixture such as a sink, shower, or floor drain designed to receive and direct wastewater into the plumbing system. Receptors play a crucial role in the overall drainage system, ensuring that liquid waste is effectively channeled away from various fixtures in a building.

A trap, while important, mainly functions to prevent sewer gases from entering the building by creating a water seal; it does not directly discharge waste materials on its own. A drain is essential for transporting waste away from a fixture but does not actively collect it. A vent pipe is critical for maintaining proper air pressure and preventing vacuum in the drainage system, but it does not deal with the collection or discharge of waste. Each of these components has a specific function, but the receptor uniquely fulfills the role of both collecting and discharging waste materials, making it the correct choice in this context.