Which prefix would your ISP likely allocate to your network?

You own a home network connecting through an always-on connection and need to assign
IPv6 addresses to your routers because you want to follow the guidelines spelled out in
RFC 3177. You want to design your network with the correct prefixes. Which prefix would
your ISP likely allocate to your network?

A.
128-bit prefix

B.
64-bit prefix

C.
47-bit prefix

D.
48-bit prefix