Explanation:

- CITES: The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) is an international agreement aiming to ensure that international trade in specimens of wild animals and plants does not threaten their survival. It provides varying degrees of protection to more than 37,000 species.

- BRICS: A group of five major emerging economies: Brazil, Russia, India, China, and South Africa. It is not related to wildlife conservation.

- GATS: The General Agreement on Trade in Services, part of the WTO agreements, focuses on international trade in services, not wildlife trade.

- OPEC: The Organization of the Petroleum Exporting Countries, focused on oil policies, is unrelated to wildlife conservation.

Correct Answer: CITES