Dwelling smoke alarms must produce an audible ____ signal for at least ____ minutes.

For dwelling smoke alarms, the requirement for an audible alarm signal is critical for ensuring the safety of occupants. The correct answer indicates that the smoke alarms must produce an audible evacuation signal for at least four minutes.

This standardized requirement is designed to alert individuals in the event of smoke detection effectively, allowing sufficient time for residents to evacuate the premises safely. The four-minute duration ensures that the alarm is not only loud enough to awaken sleeping individuals but also sustained long enough to alert everyone in the dwelling, including those who may be less attuned to the sound of the alarm. It emphasizes the importance of a clear and persistent warning in case of fire emergencies, which can be essential for saving lives and minimizing injury.

The other options, while mentioning different types of signals and time durations, do not align with the specific requirement that smoke alarms in dwelling units must adhere to. The focus on an evacuation signal is crucial, as it differentiates between general notifications and those specifically intended to prompt immediate action for safety.