Which army regulation would be referenced if you want to properly mark removable ais storage media?

To protect and mark classified and/or sensitive information stored on AIS media is contained in AR 380-19 Information Systems ecurity.  Equipment will be protected as follows:(1) AIS that have nonremovable media upon which classified files reside must be stored in an area or container approved for safekeeping of classified information per AR 380-5.(2) AIS that do not have classified files on nonremovable media should be in a locked office or building during nonduty hours, or otherwise secured to prevent loss or damage. Users will log off the computer when they leave the area.  

4because of my mind tells me to pick 4