How can an administrator monitor user activity in ArcGIS Online?

Monitoring user activity in ArcGIS Online is crucial for maintaining security, understanding usage patterns, and managing resources effectively. The correct option highlights the use of usage reports and activity logs as a means for administrators to track and analyze user interactions within the platform.

Usage reports provide insights into how many resources users are utilizing, the frequency of their access, and the types of content they are engaging with. Activity logs complement this by detailing specific actions taken by users, such as edits made to content, sharing activities, and login times. This comprehensive data helps administrators identify trends, spot unusual behavior, and ensure compliance with organizational policies.

The other options, while they might include some aspects of monitoring user activity, are not as effective. Real-time notifications can alert administrators of immediate issues but do not provide a summary or deeper insights into user behavior over time. External analytic tools may offer additional functionality but typically require integration and do not inherently reflect the specific activities within ArcGIS Online. Manually checking each user's activity is time-consuming and inefficient, making it impractical for large organizations with many users.

Overall, usage reports and activity logs represent a systematic and effective approach to monitoring user activity in ArcGIS Online.