IPv6 addresses are 128 bits in length and are written as eight groups of four hexadecimal digits. Each group is separated from the others by colons (:). The correct notation for IPv6 addresses allows for the omission of leading zeros within each block of four hexadecimal digits and the use of double colons (::) to represent consecutive blocks of zeros. However, the double colons can only be used once in an address to ensure proper expansion to the full 128 bits. Option B is the only choice that correctly represents a full IPv6 address without any abbreviation. Options A and C use double colons incorrectly, and option D represents a prefix length rather than a full address. Reference := The information is based on standard IPv6 address notation practices, which include the representation of addresses in hexadecimal format and the rules for abbreviating zeros1