Read the excerpt below and then answer the question that follows.
In 1803, President Thomas Jefferson bought the Louisiana Territory from France. One factor influencing President Jefferson's decision to make this purchase was his desire to control the Mississippi River.
Why did President Jefferson and many other Americans want to control the Mississippi River?
A. It served as an important waterway for Western farmers to ship their goods to Eastern markets.
B. It posed a geographic barrier to future settlement in Western territories.
C. It functioned as a natural barrier preventing American Indian attacks.
D. It provided a secure border between the United States and Mexico.