The correct answer is A. Conservation of Forests.
The Chipko Movement was a non-violent movement that started in the Garhwal Himalayas in 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 its goal of conserving forests. The movement also led to a change in the way that forests were managed in India. Forests are now seen as a valuable resource that needs to be protected, and the Chipko Movement is credited with helping to raise awareness of the importance of forests.
The other options are incorrect because they are not the central theme of the Chipko Movement. Option B, conservation of river water, is a related issue, but it is not the central theme of the movement. Option C, protection of birds, is also a related issue, but it is not the central theme of the movement. Option D, protection of cheetals, is a related issue, but it is not the central theme of the movement.