Which type of record must be provided immediately to residents upon request?

The active clinical record is the correct choice because it contains the most current and ongoing health-related information about a resident. This record typically includes recent treatments, evaluations, and changes in medication, making it vital for the resident's continuous care and management. By law, residents have the right to access their active clinical records promptly to ensure they can participate fully in their own healthcare decisions.

In contrast, personal health records may not be as comprehensive or up-to-date as active clinical records, while historical clinical records reflect past health information that may not be immediately relevant to present care. Medical billing records focus on financial aspects rather than the actual clinical data that is crucial for current healthcare needs. Therefore, access to the active clinical record is essential for enabling residents to stay informed about their current health status and treatment plans.