Which of the following is a primary responsibility of a lifeguard?

The primary responsibility of a lifeguard is to monitor and ensure the safety of all patrons. This involves being vigilant and attentive while observing swimmers and other individuals in and around the water. Lifeguards are trained to recognize potential hazards, respond to emergencies quickly, and take appropriate actions to prevent accidents or respond to incidents that occur. This responsibility is at the core of a lifeguard's role, as their main objective is to protect the health and safety of all individuals at the pool or beach.

Conducting swimming lessons, performing routine maintenance on pool equipment, and socializing with patrons, while they may be part of a lifeguard's duties in certain contexts, are not the foremost responsibilities. These activities can detract from their primary role, which is focused on monitoring safety and ensuring a secure environment for all participants in water activities.