Which plumbing system component is designed to convey liquid waste away from a building?

The drainage pipe is specifically designed to convey liquid waste away from a building. Its primary function is to transport wastewater from fixtures such as sinks, toilets, and showers to the building's sewage system or septic tank. Drainage pipes are typically made from materials that are resistant to corrosion and capable of handling the flow of waste, ensuring efficient movement and disposal.

In contrast, a vent pipe serves to maintain air pressure in the plumbing system, allowing wastewater to flow freely without creating vacuums or siphoning. A supply line provides potable water to fixtures and appliances, ensuring that clean water is available for use. The waste stack is a vertical pipe that carries wastewater from multiple drainage pipes to the sewer line, but it is part of a larger system rather than solely responsible for conveying waste away from the building. These distinctions clarify why the drainage pipe is the correct choice for the given function.