Correct Answer - C
IUCN or IUCNNR (international union for conservation of nature and natural resources) is now known as WCU (World conservation union). Its headquarter is at gland. Switzerland. It studies the threat to biodiversity in all parts of the world by gathering information about the geographical distribution, population size and population changes of various taxa. it prepares a red list or red data book categorising different organisms belonging to different categories.
