What is the correct simplification of the 2001:0000:000…

What is the correct simplification of the 2001:0000:0000:0234F:0000:CBFF:5CA1:A001 IPv6 address?

A.
2001::234F:0 :CBFF:5CA1:A001

B.
2001:0:0:234F:0:CBFF:5CA1:A1

C.
2001::234F:CBFF:5CA1:A001

D.
2001::234F::CBFF:5CA1:A001