What is the procedure for arming the AFT slides after the Captain's command has been heard?

The procedure for arming the AFT slides is crucial for ensuring the safety of passengers during an emergency evacuation. When the Captain's command is issued, the next steps are typically designated to specific crew members to ensure efficiency and thoroughness.

In this case, the correct answer highlights that No 2 must arm and physically check both slides, followed by visually confirming that the slides are indeed armed. This is important for the following reasons:

1. Safety Assurance: By having one trained crew member tasked with both arming and physically checking, it ensures that all steps are correctly followed. This reduces the chance of human error and increases the likelihood that the slides will deploy correctly if needed.

2. Double-Check Protocol: The physical check ensures that both slides are functioning properly. This final verification process is critical in an emergency scenario where every second counts.

3. Team Coordination: This process fosters coordination among crew members, as each has distinct roles. Empowering one crew member to handle both slides allows for more streamlined communication and action in an emergency.

Effective procedures in emergency situations increase the likelihood of a successful evacuation, which underscores why the chosen approach in the question is the most appropriate.