The correct option is "2 and 3 only" because IUCN is not an organ of the United Nations; it is a membership union comprised of government and civil society organizations that work towards conserving nature and ensuring sustainable use of natural resources. However, statement 2 is accurate as IUCN does indeed manage numerous field projects globally to promote conservation efforts. Statement 3 is also correct. While CITES is an international agreement aimed at ensuring that international trade in wild animals and plants does not threaten their survival, it remains non-binding at the national level and does not supplant national laws, thus allowing countries to implement their own regulations in addition to CITES obligations. This contextual understanding aligns with the framework of international environmental governance and the functioning of conservation organizations, which is relevant for UPSC Prelims GS Paper I.