Answer:
The United States purchased land from France so it could expand the size of the nation
Step-by-step explanation:
The statement that best explains how the Lewis and Clark expedition was a result of U.S. Foreign policy is that "the United States purchased land from France so it could expand the size of the nation"
This is evident in the fact that the Lewis and Clark Expedition that lasted between 1803 to 1806 was made after the Louisiana Purchase.
The purpose of the expedition is to establish a definite path through the newly acquired territory and develop an American presence in the territory before any other European powers attempt to claim the region.