Final answer:
The valid IPv6 address between the two examples is 2001:0db8:0000:ff00:0042:8329, as it only contains valid hexadecimal characters.
Step-by-step explanation:
The valid IPv6 address format in the examples given is 2001:0db8:0000:ff00:0042:8329. An IPv6 address is represented as eight groups of four hexadecimal digits, each group representing 16 bits or two octet. The groups are separated by colons. The address 2001:0db8:0000:0003:0000:jk00:0042:8329 is invalid because it contains 'jk' which is not a valid hexadecimal value. Hexadecimal numbers only include the digits 0-9 and the letters A-F. Therefore, the second example without any non-hexadecimal characters is the correct IPv6 address.