Which of the following is an example of an informational event?

An informational event is characterized by its function of conveying information that does not require immediate action. In this context, a system log entry indicating normal operations fits this definition perfectly. It serves to inform stakeholders about the current status of the system and confirms that all operations are functioning as expected. This type of event helps in ensuring that operations are consistent and stable but does not imply any urgency or necessity for intervention.

Other events listed do not qualify as purely informational. A system failure alert indicating downtime is a critical event that requires urgent attention and action to restore services. A scheduled maintenance completion notification, while informative, typically follows a process that may require an acknowledgment or a subsequent action related to maintaining system reliability. Additionally, a warning about potential security vulnerabilities is more of a precautionary measure that necessitates investigation and possible remedial actions to mitigate risk. Thus, the nature of these events distinguishes them from the purely informative nature of a log entry that indicates normal operations.