The correct option is
B 1992
At many places forests are being replaced or degraded. The main causes for this threat to nature are hunting and poaching by man for commercial purposes. Pollution due to chemical and industrial waste,acid deposits , introduction of alien species and reckless cutting of the forests to bring land under cultivation and habitation are also responsible for imbalance.
To protect the flora and fauna of the country the government has taken many steps:
1. 18 Biosphere Reserves have been set up in the country and 3out of them are the Sunderbans in the West Bengal, the gulf of Mannar in Tamilnadu and the Nilgiris (Kerala ,Karnataka and tamilnadu) are included in the world network of Biosphere Reserves.
2. Since 1992 the government has provided financial and Technical assistance too many botanical gardens.
3. Project Tiger, project rhino, project Great Indian Bustard and many other Eco developmental projects have been introduced.
4. Many facilities like generating awareness among the people and to educate their our flora and fauna are provided.
5. 103 national parks, 530 Wildlife sanctuaries and zoological gardens (Government of India, July 2015) are setup to take care of natural heritage.