When a network transitions from IPv4 to IPv6, how many bits does the address expand to?

A.
64 bits

B.
128 bits

C.
96 bits

D.
156 bits

Explanation:
IPv6 uses a 128-bit address, allowing 2128, or approximately 3.4×1038 addresses, or more than
7.9×1028 times as many as IPv4, which uses 32-bit addresses and provides approximately 4.3
billion addresses.
Reference: http://en.wikipedia.org/wiki/IPv6