What should lifeguards prioritize when monitoring beachgoers?

Lifeguards must prioritize constant observation of swimmers because it is their primary duty to ensure the safety of individuals in the water. Continuous monitoring allows them to detect potential dangers, such as swimmers in distress or rip currents, and respond promptly. This vigilance is crucial for preventing accidents and ensuring that all beachgoers can enjoy a safe experience.

The other choices, while they might have their own contexts, do not align with the critical responsibilities of a lifeguard. Personal calls and managing social media divert attention away from the immediate environment, which can lead to overlooking someone in need of help. Taking breaks is important for maintaining alertness, but it should not compromise the safety of those in the water. Lifeguards are trained to balance their need for breaks with the requirement to maintain effective surveillance, demonstrating that constant observation is indeed the foremost priority.