I would go with A) the fall of the Berlin Wall. When it fell, it symbolized the end of the division between East and West Germany and acted as a rallying image for the end of Communism in Europe.
The Doctrine of Enlargement is best described in the following statement: "<span>a foreign policy stance that espouses a unilateral approach to protecting the best interests of the United States."</span>
The answer is choice 4 "the purchase of the Louisiana Territory from France could lead to war with Spain"
The British founded Jamestown