Which statement is true about the command ipv6 ospf 1 area 0?

Which statement is true about the command ipv6 ospf 1 area 0?

A.
It must be issued in router global configuration mode to enable the OSPF process for IPv6.

B.
It must be issued in interface configuration mode to enable the OSPF process for IPv6.

C.
It must be issued before the network command to enable the OSPF process for IPv6.

D.
It must be issued after the network command to enable the OSPF process for IPv6.

Explanation:
http://www.6deploy.eu/workshops/kenya_20080617/IPv6%20Routing_OSPFv3_MPBGP.pdf (Slide 29)