The correct answer is C. Rachel Carson.
Silent Spring is a book written by Rachel Carson and published in 1962. It was a seminal work in the environmental movement and helped to launch the environmental movement in the United States. The book documented the detrimental effects of pesticides on the environment and human health. It was widely read and helped to change public opinion about the use of pesticides.
John Miller is a British author who has written several books on science and technology. Charles Darwin was a British naturalist who is considered to be the father of evolutionary biology. Aldo Leopold was an American ecologist and conservationist who is considered to be one of the founders of the modern environmental movement.
John Miller, Charles Darwin, and Aldo Leopold are all important figures in their respective fields. However, Rachel Carson is the author of Silent Spring, which is a well-known book about the environmental effects of pesticides.