The historic convention on biological diversity held in Rio de Janeiro in 1992 is also known as:

Correct option is A

The Rio de Janeiro convention on biological diversity is popularly known as the Earth Summit. It addressed global environmental issues and sustainable development.
1. The Earth Summit
The United Nations Conference on Environment and Development (UNCED), also known as the Earth Summit, was held in Rio de Janeiro, Brazil from June 3–14, 1992. The conference's main goal was to create a blueprint for international action on environmental and development issues. 
The Convention on Biological Diversity (CBD)
The CBD is an international treaty that was opened for signature at the Earth Summit in 1992. The CBD's goals are to: 
 Conserve biodiversity 
 Sustainably use biodiversity components 
 Fairly and equitably share the benefits from genetic resources 
 Take into account the need to share costs and benefits between developed and developing countries 
 Support innovation by local people