Which of the following can provide security against man-in-the-middle attack?

Strong authentication verifies user identity at login but does not prevent an attacker from intercepting and reading unencrypted data that is already in transit between endpoints.

A firewall filters traffic at the network perimeter but cannot stop a MITM attack occurring between two already-authenticated endpoints within or across a network.

Strong data encryption during transit directly counters MITM attacks by ensuring that intercepted communications cannot be read or tampered with without the decryption key. Protocols like TLS/SSL encrypt data end-to-end, protecting both confidentiality and integrity of the communication channel. This is the only option that addresses the core mechanism of a MITM attack - unauthorized interception of in-flight data.

Anti-virus programs detect and remove malware on host endpoints but have no capability to protect data flowing across a network from being intercepted by a third party.