Biosphere reserves are sites established by countries to promote sustainable development based on local community efforts and sound science. They are areas of terrestrial and coastal ecosystems promoting solutions to reconcile conservation of biological and cultural diversity and economic and social development through partnerships between people and nature.
They are recognized under UNESCO's Man and the Biosphere (MAB) Programme. The first biosphere reserve of the world was established in 1979, since then the network of biosphere reserves has increased to 580 in 114 countries across the world (MAB, 2012). Hence option A is correct.