What is the role of neighbor solicitation (NS) messages in the autoconfiguration of an IPv6 address?

A.
An IPv6 node sends an NS message to inform a nodeundergoing autoconfiguration that it is already using
a particular address.

B.
An IPv6 node sends an NS message for its tentative address to determine whether another node is using it.

C.
An IPv6 node sends an NS message for the global prefix to prompt other IPv6 nodes to advertise the
addresses that they are using on that prefix.

D.
An IPv6 node sends an NS message to prompt an IPv6 router on the link to advertise the global prefixes
associated with the link immediately.