What should drivers be cautious of when navigating near aircraft?

Drivers should be particularly attentive to both the sound of the engines and the movements of the crew when navigating near aircraft. The sound of the engines is significant because it can indicate whether the aircraft is in motion or preparing for takeoff or landing. Recognizing the audio cues is crucial for assessing the safety of the environment, as loud engine noises might suggest that an aircraft is about to depart or has just landed, necessitating increased awareness from drivers.

Additionally, the movements of the crew are vital indicators of what is happening around the aircraft. Ground crew members might be giving signals or performing tasks that directly affect the area around the aircraft, such as directing traffic or securing equipment. Understanding these movements helps drivers anticipate and respond appropriately to keep everyone safe.

Considering these points, being cautious about both the sound of the engines and the movements of the crew is essential, making the comprehensive choice of "All of the above" the correct one. The other option, which refers solely to the color of the aircraft, does not carry the same level of importance concerning safety information.