Under which condition can a one-rescuer assist be utilized for extricating a person at the shoreline?

The option indicating that a one-rescuer assist can be utilized for extricating a person at the shoreline is valid because when a person is responsive and can walk, they are likely able to assist themselves. This allows the rescuer to provide support and guidance rather than performing a complex or potentially hazardous extraction technique.

In situations where a person is unresponsive, the likelihood of their needing immediate medical attention makes it unsafe for a solo rescuer to attempt to assist without additional support or resources. Similarly, if a person has a suspected spinal injury, moving them without proper stabilization and additional rescuers could exacerbate the injury and pose serious risks to their health. For a responsive individual who cannot walk, it may require more than one rescuer to ensure a safe extraction technique while providing necessary assistance. Therefore, the condition where the person is responsive and able to walk allows for a straightforward and effective method of assistance without further risk.