What should No.3 and No.4 brief their ABPs about during a decompression emergency?

In the context of a decompression emergency, it's crucial that the ABPs (Able Bodied Persons) are thoroughly briefed to ensure a safe and efficient response. The instruction regarding not opening overwing exits unless instructed is particularly significant because during a decompression, opening exits prematurely can complicate the situation, potentially endangering passengers due to rapid cabin depressurization.

Properly briefing ABPs on this point helps to maintain control over the situation, ensuring that exits are only opened when it is safe to do so, as directed by the crew. This prevents any unnecessary risks during an already critical situation.

While other options involve important elements of emergency procedures, they don't emphasize the critical role of ABPs in managing exits effectively during a decompression event. For instance, understanding how to use oxygen masks and locating emergency exits is vital for personal safety, but it is the management and control of the exits that can significantly influence the overall safety of all onboard during such emergencies.