Before an airplane can move on the surface, what must be ready for evacuation?

The correct answer highlights that before an airplane can move on the surface, it is crucial for the automatically deployable emergency evacuation assisting means to be ready. This refers to systems and equipment integrated into the aircraft that can facilitate a swift and safe evacuation during an emergency. These systems are designed to automatically deploy under specific conditions, ensuring that, in the event of an urgent situation requiring evacuation, passengers can exit the aircraft quickly and safely.

Having these systems prepared is a fundamental safety protocol governed by regulations to ensure the readiness of an aircraft and its crew to respond effectively to emergencies. This aspect is critical, as time can be of the essence in evacuation scenarios, and ensuring that these means of assistance are operational is vital for the safety of all aboard.

The other options, while important in various contexts, are not the primary requirements for surface movement readiness. Emergency lights are important for visibility and assisting in evacuations but do not specifically pertain to the ability to execute an evacuation effectively. Passenger safety briefings are crucial for informing passengers but typically occur prior to takeoff rather than being an immediate requirement for moving on the ground. Medical supplies are essential for in-flight emergencies but are not directly related to the readiness for an evacuation process in the context of surface movement.