Final answer:
After the independence declarations by three Yugoslav republics in 1991, ethnic conflicts led to violence, particularly in regions with Serbian minorities, resulting in a violent breakup of Yugoslavia.
Step-by-step explanation:
After three of the republics of Yugoslavia declared their independence in 1991, the region descended into ethnic and civil strife. The correct answer to the student's question is A. Conflicts between the diverse ethnic groups in these countries became violent.
As Croatia, Slovenia, and Macedonia declared their independence, followed by Bosnia and Herzegovina in 1992, violence erupted, particularly in areas with Serbian minorities such as Croatia and Bosnia-Herzegovina, and in the Serbian province of Kosovo. The Serbian-dominated Federal Republic of Yugoslavia, consisting of Serbia and Montenegro, remained. The situation was exacerbated by the fact that throughout the 1990s, Yugoslavia had tried to stand apart from the Eastern Bloc and the Soviet Union, with the latter's collapse contributing to the centrifugal forces tearing the country apart.