Which side of the ERJ 175 includes three passenger supplemental oxygen masks?

The correct answer indicates that both the A/CR (aft cabin right) and A/CL (aft cabin left) sides of the ERJ 175 are equipped with three passenger supplemental oxygen masks. This configuration is designed to ensure that in the event of cabin depressurization, there are adequate oxygen supplies available for passengers on both sides of the cabin.

Having oxygen masks on both sides enhances the overall safety by allowing easier access for passengers, regardless of where they are seated. This redundancy is a standard safety feature in aircraft design, ensuring that there is a reliable source of supplemental oxygen readily available to passengers.

In this case, the other options incorrectly suggest that the oxygen masks are only present on one side or not at all, which does not reflect the actual configuration designed for passenger safety in the ERJ 175. Thus, the provision of oxygen masks on both sides underscores the aircraft's commitment to passenger safety and adherence to regulatory safety standards in aviation.