What major contribution did Theodore Roosevelt make to the environmental
movement as president?

After becoming president, Theodore Roosevelt used his authority to protect wildlife and public lands by creating the United States Forest Service, and establishing 150 national forests, 51 federal bird reserves, 4 national game preserves, 5 national parks, and 18 national monuments.

Explanation:

Well the answer pretty much said it-

(d) he had been a leader of the sons of liberty.