IUCN (The International Union For Conservation Of Nature And Natural Resources) headquarters is at

The correct answer is A. Gland, Switzerland.

The International Union for Conservation of Nature and Natural Resources (IUCN) is an international organization that helps the world find practical, innovative solutions to our most pressing environmental and development challenges. IUCN’s work is guided by its six strategic priorities:

• To conserve the integrity and diversity of the natural world, and to ensure that any use of natural resources is sustainable.
• To promote sustainable development through the conservation of nature.
• To support the fair and equitable sharing of benefits arising from the use of genetic resources.
• To strengthen the capacity of IUCN and its members to achieve its mission.
• To increase understanding and support for the work of IUCN.

IUCN is the world’s oldest and largest global environmental organization, with more than 1,400 member organizations and a network of more than 10,000 experts. IUCN’s headquarters are located in Gland, Switzerland.

The other options are incorrect.

• Option B, Paris, France is the headquarters of UNESCO (United Nations Educational, Scientific and Cultural Organization).
• Option C, Vienna, Austria is the headquarters of the International Atomic Energy Agency (IAEA).
• Option D, New York, USA is the headquarters of the United Nations (UN).