The correct answer is D. The establishment of a national park system to protect the wilderness and preserve resources.
Explanation
According to the fragment of the question, it can be affirmed that the concerns expressed by Roosevelt in it led him to focus on the objective of preserving the natural resources that the United States had and had been exploited without the control they deserved. For example, Franklin D. Roosevelt expresses concern by asking "what will happen when our forests are gone, when the coal, the iron, the oil, and the gas are exhausted, when the soils have still further impoverished and washed into the streams, polluting the rivers, denuding the fields and obstructing navigation". Therefore, Franklin D. Roosevelt established the Single System of National Parks on June 10, 1933, as President of the United States. Therefore, the correct answer is D. The establishment of a national park system to protect the wilderness and preserve resources.
