Which rule applies to the deployment of guidelines?

The deployment of guidelines in a cavern diving scenario is crucial for ensuring safety and navigation. The correct choice highlights an important practice: the person responsible for managing the reel should enter the cave first and be the last to exit. This practice ensures that the guideline remains taut and properly secured as divers move in and out of the cave. If the reel person enters first, they can establish a clear path for others to follow, minimizing the risk of entanglement while providing a reliable means for navigation back to the entrance.

Moreover, having the reel person exit last helps ensure that the guideline is properly retracted and aids in the safe exit of all divers. This sequential approach to guideline deployment and retrieval promotes order and minimizes potential hazards associated with multiple divers navigating simultaneously.

Other options may suggest alternative practices, but they do not prioritize the crucial role of the reel operator in both establishing and maintaining the guideline system for all divers involved in the dive.