The United Nations Framework Convention on Climate Change (UNFCCC) is and international treaty drawn at

The United Nations Framework Convention on Climate Change (UNFCCC) was adopted in connection with the United Nations Conference on Environment and Development (the Earth Summit) held in Rio de Janeiro in June 1992. Authoritative sources state that the UNFCCC, along with the Convention on Biological Diversity and the Convention to Combat Desertification, were adopted at UNCED (Rio) [1]. The UNFCCC secretariat records that the Convention was adopted on 9 May 1992 and was opened for signature at the Rio conference (3–14 June 1992) and thereafter at UN Headquarters . Other summaries likewise note that the Rio Earth Summit spawned the three “Rio Conventions,” including the UNFCCC [2]. Hence option (2) is correct.

Sources

1. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 24: Climate Change Organizations > 1992 "l > p. 321
2. [2] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 29: Environment Issues and Health Effects > fuo+zo > p. 427