Correct option is B
The Gulf of Mannar Marine Biosphere Reserve in Tamil Nadu is India’s first marine biosphere reserve, hosting a diverse wildlife marine ecosystem with over 4,200 species of flora and fauna, including coral reefs, seagrasses, turtles, and dugongs.
Knowledge Booster:
It was declared a Biosphere Reserve in 1989.
It covers 10,500 sq. km with 21 islands between Rameswaram and Tuticorin.
Dugongs (sea cows) are listed as vulnerable species under the IUCN Red List.