What must be the power status of the galley and LAV water systems prior to boarding?

The power status of the galley and LAV water systems must be "On prior to boarding and takeoff" to ensure that all necessary facilities and services are operational before passengers enter the aircraft. Having the systems powered on allows the flight attendants to perform essential pre-flight checks, including confirming that water is available for use in the lavatories and that galley services can be prepared for the passengers.

It is crucial to have these systems on prior to boarding so that flight attendants can attend to any hygiene needs and food or beverage preparations that may be required before the aircraft departs. This helps to ensure a smooth boarding process and enhances passenger comfort.

Other choices, such as having the power off or only on during descent, would not meet operational safety requirements or passenger convenience, since passengers would not have access to lavatory facilities or necessary services during crucial boarding and initial flight phases. Therefore, keeping the systems on before boarding and during takeoff is essential for a safe and pleasant travel experience.