When firewall policy authentication is enabled, which protocols can trigger an authentication challenge? (Choose two.)

SMTP (email sending) is typically a server-to-server or client-to-server protocol that does not inherently support user-interactive authentication challenges suitable for firewall policies.

POP3 (email receiving) is also typically a client-to-server protocol, and while it involves user credentials, it's not a protocol that commonly triggers a firewall-level interactive authentication challenge.

HTTP is a primary protocol used for web-based authentication, where the FortiGate can redirect users to a captive portal to perform authentication.

FTP traffic can also be intercepted by the FortiGate to trigger an authentication challenge, often via a proxy-based approach, requiring users to authenticate before accessing FTP resources.