which are the four existing Regional Internet Registry (RIR’s)?

Your company trainee Sandra asks you which are the four existing Regional Internet Registry (RIR’s)?

A.
APNIC, PICNIC, ARIN, LACNIC

B.
RIPE NCC, LACNIC, ARIN, APNIC

C.
RIPE NCC, NANIC, ARIN, APNIC

D.
RIPE NCC, ARIN, APNIC, LATNIC

Explanation:
All other answers include non existing organizations (PICNIC, NANIC, LATNIC). See http://www.arin.net/library/internet_info/ripe.html