Final answer:
The correct option to use to decrypt a file encrypted using asymmetric encryption is the private key.
Step-by-step explanation:
To decrypt a file that is encrypted using asymmetric encryption, the correct option to use is the private key. Asymmetric encryption, also known as public key encryption, uses a pair of keys: a public key for encryption and a private key for decryption.
The encryption process uses the recipient's public key to encrypt the file, and then only the recipient with the corresponding private key can decrypt the file.