The correct option is C IUCN
IUCN
IUCN (International Union for Conservation of Nature and Natural Resources) is an organisation that publishes the Red data book. The Red data book is the book having records of all the endangered species belonging to animal, plant and fungi kingdom.
UNEP
UNEP stands for United Nations Environment Programme. This programme deals with environmental issues globally.
WWF
WWF stands for World Wildlife Fund, it is responsible for the conservation of wildlife.
GEF
GEF stands for Global Environment Facility, it provides financial assistance for conservation of biodiversity.
Final answer
a. IUCN.