Refer to the exhibit. If R1 is configured for 6to4 tunneling, what will the prefix of its IPv6 network be?

A.
1723:1100:1::/48

B.
FFFF:AC1F:6401::/16

C.
AC1F:6401::/32

D.
2002:AC1F:6401::/48

E.
3FFE:AC1F:6401::/32