The correct answer to this question is C. EFS files display in green by default. In the Microsoft Windows operating system, EFS stands for Encrypting File System. This technology provides filesystem-level encryption and enables files to be transparently encrypted. This helps to protect confidential data from users with malicious intent who have physical access to the computer.
Users can turn on EFS features through Windows Explorer by using the code cipher.exe in the command-line utility. Windows communicates the fact that the file is encrypted using the EFS file encryption feature through green letters, so the user is aware of the encryption.