The correct option is
C Protection and conservation of trees and forests
Chipko movement or Chipko Andolan started in Reni village in Garhwal in 1974 to protect the trees by hugging them and not allowing felling of the trees. Hence option c is correct.
Sunderlal Bahuguna, one of the famous environmentalists of India is the leader of the Chipko movement. He spent a major part of his life fighting for the preservation, protection and conservation of trees and forests in the Himalayas.
This movement was started by Gaura Devi, a local woman. She along with her friends showed enormous bravery in protecting trees from felling by contractors in a small village of Uttarakhand. The Chipko movement quickly spread across the communities and forced the government to think about the need for the conservation of forest.
Green revolution refers to the great increase in production of food grains (wheat and rice) that resulted from the introduction of new, high-yielding varieties, in the mid-20th century. So option d is green revolution.
White revolution refers to the increase in milk production. This made India self-dependent in milk production. Hence option a is white revolution.