Biosphere reserves are conserved specific places for the huge diversity or variety of life that they hold.

The correct option is A Biosphere reserves

Biosphere reserves are protected, specific places for the conservation of wildlife, plant and animal resources and traditional life of the tribals living in the area. The Indian government has established 18 Biosphere Reserves in India which protects larger areas of natural habitat (than a National Park or Animal Sanctuary), and often include one or more National Parks or preserves.