An accountant is transferring information to a bank over FTP. Which of the following mitigations should the accountant use to protect the confidentiality of the data?

Encryption is the correct mitigation because it transforms data into an unreadable format, protecting its confidentiality during transmission over an insecure protocol like FTP. If intercepted, the encrypted data would be unintelligible without the correct decryption key. Tokenization replaces sensitive data with a non-sensitive equivalent (a token) but is typically used for data at rest in databases, not for securing data in transit over FTP. Data masking obscures sensitive data by replacing it with realistic but false data, primarily for non-production environments like testing, not for live data transfer. Obfuscation makes code or data harder to understand but doesn't provide the strong cryptographic protection needed for confidentiality during transmission.