The correct answer is D.
By 1989, the Soviet Union was about to collapse and many of its satellite nations in Eastern Europe in political turmoil. Movements for democracy and freedom were gaining strength, starting in Poland but spreading rapidly. In Eastern Germany, the socialistic government proved inflexible in dealings with the demands for change. In response, thousands of East Germans traveled as tourists to Hungary and declared that they would not return home.
They hoped to cross from Hungary into Austria and then into West Germany. Hungary was reluctant to open its borders first but as the the numbers of East Germans increased, they began to fear a refugees crisis. Hungary itself was in a period of dramatic political change and willing to fight communism. With opening its border, nearly 8,000 East Germans fled to the West.
This flow of people proceeded the fall of the Berlin Wall in November 1989 and the unification of Germany.
