The waste from an automatic clothes washer must discharge through what mechanism?

The correct choice involves using an air break or air gap for the discharge of waste from an automatic clothes washer. This mechanism is designed to prevent contaminated water from flowing back into the clean water supply. An air break typically consists of a physical separation between the discharge hose and the waste plumbing system, ensuring that any backflow is stopped by the distance. An air gap provides the same prevention against siphoning and flooding by maintaining a gap between the water outlet of the appliance and the drain.

In contrast, a direct connection would not provide this necessary protection, as it could allow for potential cross-contamination between potable water and wastewater. A drain pipe is too broad a term without specifying that it is part of a safe discharge system. An overflow pipe is specifically for handling excess water from a tank or fixture, not the primary discharge of a washing machine. Therefore, the air break or air gap is the safest and most effective mechanism for discharging waste from a clothes washer.