Correct Option: B

Nilgiris Biosphere Reserve, established in 1986, is India's first and foremost biosphere reserve. It is situated in the Western Ghats and Nilgiri Hills ranges of South India. The reserve encompasses 5,520 km² in the states of Tamil Nadu (2537.6 km²), Karnataka (1527.4 km²) and Kerala (1455.4 km²). It forms an almost complete ring around the Nilgiri Plateau.