The correct answer is: B. Sunderlal Bahuguna.
The Chipko movement was a forest conservation movement that started in the Garhwal Himalayas of India in the early 1970s. The movement was started by a group of women who protested against the felling of trees in their forests. The women hugged the trees to prevent them from being cut down, and this act of defiance became the symbol of the Chipko movement.
The Chipko movement was successful in preventing the felling of trees in many areas, and it also helped to raise awareness of the importance of forests. The movement has been credited with helping to change the way that forests are managed in India, and it has inspired similar movements around the world.
A. Engler is a German botanist and ecologist who is best known for his work on the relationship between plants and the environment. He is not associated with the Chipko movement.
C. Medha Patkar is an Indian social activist who is best known for her work on the Narmada Bachao Andolan (Save the Narmada Movement). She is not associated with the Chipko movement.
D. None of these is the correct answer.