You are right, it is D. Tourism
It was the Truman Doctrine that established that the United States should give
political, military, and economic support to democratic nations threatened by<span> authoritarian powers</span>. These authoritarian powers were largely communist at the time.
America's victory at Yorktown helped the Continental Army remove all British barracks from New Jersey. This was the final battle during the American Revolution. The Americans won with the help of the French.