Which Salesforce feature allows a developer to see when a user last logged in to...

To perform historical auditing and analysis of user behavior—such as tracking the last login time—Salesforce provides Event Monitoring (Option C). This feature captures a wide range of "Event Types," including logins, logouts, URI (page) clicks, and API calls.

These events are stored in EventLogFile objects. Each day, Salesforce generates log files for the previous day's activity. A developer can query these files or use tools like the Salesforce Event Log File Browser to see a comprehensive history of user logins. This is the correct choice when real-time alerts are not necessary and the goal is to analyze patterns over time.

Option A refers to Change Data Capture, which is for tracking record changes, not user sessions. Option B is for the standard Salesforce Calendar. Option D (Developer Log) is used for debugging Apex and system execution in the short term and does not provide a reliable or long-term history of user login events. Event Monitoring provides the high-fidelity audit trail required for compliance and security analysis.