The correct option is Nilgiri.
Explanation
Biosphere Reserves are large, protected areas meant for the conservation of wildlife, plant resources, and traditional life of the tribal communities living in the area. The Government of India has established 18 Biosphere Reserves to protect larger areas of natural habitat.
Chronological Analysis:
- Nilgiri Biosphere Reserve: Established in 1986, this was the first Biosphere Reserve in India. It is located in the Western Ghats and spans across the states of Tamil Nadu, Kerala, and Karnataka.
- Nanda Devi Biosphere Reserve: Established in 1988 in the state of Uttarakhand.
- Nokrek Biosphere Reserve: Established in 1988 in the Garo Hills of Meghalaya.
- Manas Biosphere Reserve: Established in 1989 in Assam.
Key Takeaway: The Nilgiri Biosphere Reserve (1986) is the oldest Biosphere Reserve in India, followed shortly by Nanda Devi and Nokrek in 1988.