Final answer:
The correct immediate action for a bench technician who discovers a backup server with disconnected hard drives is to call the IT supervisor to report the situation.
Step-by-step explanation:
When a bench technician finds a backup server with its case open and hard drives disconnected, the first step they should take is b. Call the IT supervisor. The discovery of disconnected drives containing sensitive patient medical data could indicate a security breach or serious procedural error. By contacting the IT supervisor, the technician ensures that the issue is escalated to the appropriate authorities who will initiate procedures such as incident response and investigation.
Without knowledge of why the drives were disconnected, attempting to reconnect them (a. Reconnect the hard drives) could lead to further issues or tampering with potential evidence. Documenting the scene (c. Document the scene) is important but should come after notifying the supervisor. Powering off the server (d. Power off the server) might be part of an incident response, but this action should be instructed by the IT supervisor or according to established protocols.