In which locations would you find PBEs on the A321 aircraft?

The correct choice indicates the locations of the Protective Breathing Equipment (PBE) on the A321 aircraft. PBEs are essential safety devices used to provide crew members with a source of breathable air in case of smoke or fire.

In the A321, the proper placement of PBEs is at strategic locations to ensure easy access in emergencies. Finding two PBEs in the forward overhead bin on the left side (FWD OHB AC L) allows the crew members to quickly retrieve them during a critical situation at the front of the cabin. Additionally, having one PBE in the aft overhead bin on the left side (AFT OHB AC L) ensures that there is also equipment available towards the rear of the aircraft. This distribution of PBEs enhances safety measures by ensuring they are accessible from different points within the cabin, improving the crew's ability to respond promptly to emergencies.

This configuration also aligns with standard safety protocols which aim to have necessary emergency equipment distributed throughout the aircraft to maximize accessibility.