JAVA/Sun Exam Questions

How can this functionality be enabled?

By default, sshd is not configured to tunnel X11 connections. How can this functionality be enabled?

A.
run the ssh command with the -X option

B.
run the sshd command with the -X option

C.
set X11Forwarding to yes in /etc/ssh/ssh_config

D.
set X11Forwarding to yes in /etc/ssh/sshd_config