The correct answer is C. All activities restricted.
Reserve forests are a type of protected area in India that are managed by the government. They are designated for the conservation of natural resources, such as forests, wildlife, and water. Activities that are not related to conservation are generally prohibited in reserve forests.
Option A is incorrect because all activities are not permitted in reserve forests. Option B is incorrect because some activities are permitted in reserve forests, but only if they are related to conservation. Option D is incorrect because all activities are not restricted in reserve forests.