Which of the following describes how a professional lifeguard should be prepared for their job?

The most appropriate description of how a professional lifeguard should be prepared for their job is one that includes being mature, courteous, and consistent. Maturity is essential for lifeguards, as they must handle stressful and potentially dangerous situations with composure and sound judgment. Courteous behavior is critical because lifeguards interact with the public and need to communicate rules and guidelines effectively, ensuring that patrons feel safe and attended to. Consistency in their actions and responses contributes to a reliable environment, allowing swimmers to trust that lifeguards will react appropriately during emergencies and enforce safety protocols consistently.

In the other options, traits such as inconsiderate, immature, and negative do not align with the responsibilities and expectations of a lifeguard. Similarly, being careless would contradict the need for vigilance, attention to detail, and proactive risk management that lifeguards must exhibit in their roles. Professionalism is best represented by the qualities of maturity, courtesy, and consistency.