What is a visible and audible feature of the alarm panel?

The visible and audible feature of the alarm panel is indicated by the term "Normal." This setting represents the standard operational condition of the alarm system, typically expressed through visual signals such as indicator lights and audible signals like beeps or alerts. When the system is in a normal state, it means that all systems are functioning correctly, and there are no faults or alarms triggered.

In contrast, the other options refer to different states or features of the alarm system that are not primarily focused on indicating a normal operational state. "Manual Override" typically allows for bypassing automatic functions, which may not provide a visible or audible signal by itself. "Standby" indicates a dormant phase where the system may not be actively monitoring for alarms. Lastly, "Quiet" would imply that the audible alarm is disabled, thus lacking the audible feature. Hence, "Normal" is the appropriate choice for describing a state that is both visible and produces sound on the alarm panel.