Which statement is true?
A.
An IPv6 address is 64 bits long and is represented as hexadecimal characters.
B.
An IPv6 address is 32 bits long and is represented as decimal digits.
C.
An IPv6 address is 128 bits long and is represented as decimal digits.
D.
An IPv6 address is 128 bits long and is represented as hexadecimal characters.