How many PBEs (Protective Breathing Equipment) are in the cabin?

The correct answer reflects the standard practice for equipping aircraft cabins with Protective Breathing Equipment (PBE). PBEs are critical safety devices that provide crew members with a supply of breathable air in emergency situations, particularly during smoke or fire events.

In commercial aviation, having two PBEs readily available in the cabin is a common configuration. This ensures that at least two crew members can don the equipment simultaneously to effectively manage in-flight emergencies. The availability of multiple units allows for a coordinated response to situations that may arise in both the forward cabin and in the aft cabin, enhancing the safety and preparedness of the flight crew.

The other options suggest fewer or more units than standard practice, which could compromise the safety protocols necessary for effective emergency responses during flight. Having the right amount of PBEs ensures that the crew can effectively navigate challenges while maintaining passenger safety.