What are two mandatory configuration steps to enable MPLS in an all Cisco networks? (Choose two)

A.
router (config)# mpls

B.
router (config)# ip cef

C.
router (config-if)# mpls ip

D.
router (config-if)# mpls label protocol ldp

Explanation:

ip cef
To enable Cisco Express Forwarding (CEF) on the route processor card, use the ip cef command in global configuration mode.
ipcef [distributed]
mpls ip (interface configuration)
To enable MPLS forwarding of IPv4 packets along normally routed paths for a particular interface, use the mpls ip interface configuration command.
Reference:
http://www.cisco.com/en/US/products/sw/iosswrel/ps1831/products_command_reference_chapter09186a00800