A system administrator has been tasked with securing data at rest for a company's document storage server, ensuring maximum confidentiality. Which of the following solutions would be the MOST appropriate to accomplish this task?
Ensure Secure Socket Layer (SSL)/Transport Layer Security (TLS) is enabled on the server.
Utilize a VPN with robust encryption for accessing documents remotely.
Implement full disk encryption on the document storage server drive.
Encrypt each document individually with a unique key.