Which step should the administrator take to obtain this information?

Refer to the exhibit.

A network administrator has set up MPLS on the switches shown in the exhibit. The administrator wants to verify that PE-1 can use MPLS to forward traffic to Site 3, as well as see the labels used along the path.

Which step should the administrator take to obtain this information?
A . Run a tracert to an IP address at Site 3 using the MPLS option.
B . Use the display command to view MPLS LDP neighbors.
C . Debug LDP and ping an IP address at Site 3.
D . Use the display command to view MPLS Label Forwarding Information Base (LFIB).

Answer: A

Explanation:

Classic Traceroute in MPLS environment In order to better understand the routing path and aid in troubleshooting, it is desirable to see the MPLS labels used for packet forwarding in the traceroute command output.

References: http://blog.ine.com/2008/11/24/mpls-ping-and-traceroute/