Answer:
The correct answer is C. It tripled the size of the United States.
Explanation:
A is incorrect, because as the name implies, the Louisiana Purchase was a transaction, not a military conflict. B is incorrect, as evidenced by a map. D is incorrect, because Louisiana, at the time, did not refer to a state, but a large swath of territory. E is incorrect, because most of the land involved in the Louisiana Purchase was not coastal.
