Which option is a valid IPv6 address?

Which option is a valid IPv6 address?
A . 2001:0000:130F::099a::12a
B . 2002:7654:A1AD:61:81AF:CCC1
C . FEC0:ABCD:WXYZ:0067::2A4
D . 2004:1:25A4:886F::1

Answer: D

Explanation:

http://www.ipv6.com/articles/general/IPv6-Addressing.htm

IPv6 Address Notation

IPv6 addresses are denoted by eight groups of hexadecimal quartets separated by colons in between them.

Following is an example of a valid IPv6 address:

2001:cdba:0000:0000:0000:0000:3257:9652

Any four-digit group of zeroes within an IPv6 address may be reduced to a single zero or altogether omitted.

Therefore, the following IPv6 addresses are similar and equally valid:

2001:cdba:0000:0000:0000:0000:3257:9652

2001:cdba:0:0:0:0:3257:9652

2001:cdba::3257:9652

The URL for the above address will be of the form:

http://[2001:cdba:0000:0000:0000:0000:3257:9652]/