Which option of the gpg command is used to create an encrypted version of a file?

The option of the gpg command used to create an encrypted version of a file is the one that specifies symmetric encryption. This is achieved with the "-c" option, which allows the user to encrypt a file using a passphrase. When this option is used, GnuPG will prompt for a passphrase, which will be required later to decrypt the file. This method is particularly useful for situations where the user prefers to manage a single passphrase for encryption and decryption instead of using public and private key pairs.

In contrast, other options such as "-d" and "--decrypt" are intended for decryption purposes, allowing users to retrieve the original file from its encrypted state, while "--encrypt" is specifically meant for the encryption process using public-key encryption methods rather than symmetric ones. Thus, the correct choice focuses on the specific mechanism that effectively creates an encrypted version of the file.