During the preflight inspection of the megaphone on the ERJ 175, what must be done?

The correct response is to squeeze the handle for audible clicking sounds during the preflight inspection of the megaphone on the ERJ 175. This action is essential because it confirms that the megaphone is operational and ready for use in an emergency situation where it may be necessary to communicate effectively with passengers or crew. The audible clicking sound indicates that the internal mechanism is functioning correctly, ensuring that the device will amplify sound when needed.

While checking the battery level, conducting a visual inspection for damage, and ensuring that the megaphone is secured in its storage location are all important aspects of preflight safety checks, the unique functionality of the megaphone specifically relies on the handle being squeezed to confirm that it works properly. Therefore, focusing on the operational readiness through the action of squeezing the handle is the primary reason why this option is the correct answer.