When attempting to send a file to another user securely with GPG, which of the following actions must be done?

Encrypting with your own public key would mean only your private key could decrypt it, which is not useful for sending a file securely to another user.

When encrypting a file for another user with GPG, you use their public key because only their corresponding private key can decrypt the data, ensuring confidentiality and that only the intended recipient can read the file. This asymmetric encryption principle guarantees that even if the encrypted file is intercepted, it remains unreadable to anyone without the recipient's private key.

Encrypting with your private key is typically used for digital signing to prove authenticity and integrity, not for ensuring confidentiality for another recipient.

You cannot encrypt a file with someone else's private key, as private keys are kept secret by their owner.

Signing a file with your public key is incorrect; you sign with your private key to prove authenticity and integrity, while the recipient verifies with your public key.