What must be functioning on the AED for it to be operational?

The operational status of an Automated External Defibrillator (AED) is indicated by the illumination of the green power indicators. These lights serve as a clear signal that the device is ready for use and functioning correctly. When the green indicators are illuminated, it shows that the AED has successfully passed internal self-checks, ensuring that its crucial components, such as the battery and monitoring systems, are operational.

While regular checks of the AED and ensuring that all sections are in order are important for overall maintenance and readiness, it is the state of the power indicators that confirms immediate operational capability. Thus, the correct response emphasizes the significance of the green power indicators, which provide direct assurance that the AED is ready to be deployed in a medical emergency scenario.