An IOS SSL VPN is configured to forward TCP ports. A remote user cannot access the corporate FTP site with a Web browser. What is a possible reason for the
failure?

A.
The user’s FTP application is not supported.

B.
The user is connecting to an IOS VPN gateway configured in Thin Client Mode.

C.
The user is connecting to an IOS VPN gateway configured in Tunnel Mode.

D.
The user’s operating system is not supported.

Explanation:
http://www.cisco.com/c/en/us/support/docs/security/ssl-vpn-client/70664-IOSthinclient.html Thin-Client SSL VPN (Port Forwarding)
A remote client must download a small, Java-based applet for secure access of TCP applications that use static port numbers. UDP is not supported. Examples
include access to POP3, SMTP, IMAP, SSH, and Telnet. The user needs local administrative privileges because changes are made to files on the local machine.
This method of SSL VPN does not work with applications that use dynamic port assignments, for example, several FTP applications.