Final answer:
Roosevelt, an avid conservationist, likely supported the establishment of the Grand Canyon as a national park and the Civilian Conservation Corps' projects, like dam construction, due to his historical actions and policies favoring environmental preservation and job creation.
Step-by-step explanation:
Roosevelt most likely supported the establishment of the Grand Canyon as a national park (B) and the creation of the Civilian Conservation Corps to construct dams (D).
President Roosevelt was a passionate conservationist who took considerable action to preserve the United States' natural resources and beauty. Under the supervision of Gifford Pinchot, the first chief of the U.S. Forestry Service, Roosevelt established several habitats for environmental conservation. His enduring accomplishments include the creation of national parks and national monuments designed specifically for preservation. Hence, the establishment of the Grand Canyon as a national park aligns with his dedication to preserving natural wonders.
Additionally, Roosevelt's New Deal programs included the Civilian Conservation Corps (CCC), which sought to alleviate unemployment with environmental conservation projects. The CCC involved young men in various conservation projects, including the construction of dams. This initiative corresponds with Roosevelt's interest in both conservation and providing work during the Great Depression. Considering Roosevelt's policies and actions, it is evident that he would have likely supported both the conservation of natural landmarks and projects merging environmental and societal benefits.