Which Cisco IOS SAF Forwarder configuration is correct?

Refer to the following exhibit.

Which Cisco IOS SAF Forwarder configuration is correct?

A.
Exhibit A

B.
Exhibit B

C.
Exhibit C

D.
Exhibit D

Explanation:
Incorrect answer: B, C, D

Summary steps to configure IOS SAF forwarder is given below
1. enable
2. configure terminal
3. router eigrp virtual-instance-name
4. service-family {ipv4 | ipv6} [vrf vrf-name] autonomous-system autonomous-system-number
5. topology base
6. external-client client_label
7. exit-sf-topology
8. exit-service-family
9. exit
10. service-family external-client listen {ipv4 | ipv6} tcp_port_number
11. external-client client-label
12. username user-name
13. password password-name
14. keepalive number
15. exit
Link: http://www.cisco.com/en/US/docs/ios/saf/configuration/guide/saf_cg_ps11280_TSD_Products_Configuration_Guide_Chapter.html