Explanation
Correct option is A)
Man and the Biosphere Programme (MAB) is an Intergovernmental Scientific Programme that desires to form a scientific basis in improving relationships between people and their environments.It was launched by UNESCO in 1971. It focusses the attention of people on the impact of their today’s actions on tomorrow’s world. By doing this it thereby increases people’s ability to sustain their natural resources.
So, the correct answer is '1971'.