If a User Agent That Does Not Support Authentication Tries

If a user agent that does not support authentication tries to request content through a connection on which the ProxySG requires authentication, how can you best resolve the issue?

A) Identify the TCP ports used by the user agent, and create a proxy service to bypass such traffic.
B) Identify an HTTP header that identifies the user agent, and then write policy to exempt matching transactions from authentication.
C) Identify the IP address of the user agent, and then write policy to exempt matching transactions from authentication.
D) You cannot do this.