Which historical event are the best examples of "balkanization?"
a. When India split up into India, Pakistan, and Bangladesh after gaining independence from Britain, many people were killed during the migrations by rival ethnic groups
b. the ethnic clean

The best examples of "balkanization" would be a, b, and c. These are all examples of tensions between different ethnic or religious groups leading to conflict in the region. This often involves changes in borders and/or population relocations leading to instability and violence. In the case of a and b, the tensions between different groups led to the splitting up of countries or regions. In the case of c, the sectarian tensions have resulted in huge amounts of violence and atrocities.