What is the first step a security officer should take upon observing a disturbance?

The correct choice highlights the importance of assessing the situation and ensuring personal safety before taking any further action. A security officer's primary responsibility is to maintain safety, which begins with understanding the nature of the disturbance. By evaluating the situation, the officer can determine the level of threat involved, the number of individuals engaged in the disturbance, and whether they need assistance.

Personal safety is crucial; if the situation is dangerous, the officer must not put themselves at risk unnecessarily. Once an assessment is made and safety is ensured, the officer can decide on the appropriate response, whether it involves calling for backup, intervening, or contacting law enforcement.

The other options suggest immediate actions that might overlook the necessity for situational awareness. Calling for backup without assessing the situation might lead to unnecessary escalation, while intervening directly could pose risks if the disturbance is volatile. Contacting law enforcement as the first action could delay timely intervention if the situation allows for a resolution at the security officer's level. Hence, assessing the situation and ensuring safety first is the appropriate foundational step.