How should passengers be instructed to position themselves during a crash brace position?

The crash brace position is designed to protect passengers from injury during an impact by minimizing movement and maximizing safety. The correct position involves folding the legs and resting the head on the arms while bracing against the seat. This configuration helps to stabilize the body and ensures that the head and neck are protected, reducing the risk of severe injury.

Positioning the legs in a folded manner helps to provide a stronger base of support and reduces the chances of leg injuries during a sudden event. Additionally, resting the head on the arms acts as a cushion and can help to prevent whiplash or head trauma caused by sudden movements or impacts.

Other techniques described in other options do not offer the same level of protection or consider the impact forces that might be experienced during a crash. For instance, lying flat on the back could expose vital areas to injury and does not provide an effective brace against the seat. Keeping arms raised above the head could lead to flailing during an impact, increasing the risk of arm and neck injuries. Lastly, requiring passengers to stand is not safe or practical during a crash scenario, as it would severely compromise their stability and control, increasing the likelihood of injury.