What type of materials are typically used for plumbing drains?

The correct choice highlights that plumbing drains are commonly constructed from either metal or plastic materials. Metal is often employed for its durability, strength, and resistance to corrosion, especially in environments that may experience high temperatures or pressures. Copper and stainless steel are two of the most frequently used metals in plumbing applications due to their longevity and reliability.

Plastic, such as PVC (polyvinyl chloride) and ABS (acrylonitrile butadiene styrene), is also widely used for drainage systems due to its lightweight nature, ease of installation, and corrosion resistance. These materials are particularly popular in residential plumbing because they can easily be molded and fitted into various configurations.

The other options indicate limitations that do not reflect the versatile nature of plumbing materials. Only using metal would restrict the variety and applications of drain systems, as many scenarios benefit from plastic’s properties. Similarly, stating that only plastic is used fails to acknowledge the strengths provided by metal components. Lastly, because plumbing requires materials that can effectively manage water flow and resist degradation, the mention of wood or stone is unsuitable, as these materials are not typically feasible or effective in drainage systems.