While you didn't provide us with any concrete answers, this relationship is something related to an alliance, but in reality isn't one because the smaller country is only doing this because they're afraid of repercusions.
The correct answer is B, the National Road.
The National Road was the first major managed road in the United States built by the federal government. Carried out between 1811 and 1837, the 1,000-kilometer route connected the Potomac and the Ohio River and was one of the western tracks for thousands of settlers.
Construction began westward in 1811 at Cumberland, Maryland, on the Potomac River. After the financial panic of 1837 and the ensuing economic depression, funds from Congress were dry and construction was halted in Vandalia, Illinois.