Which of the Following Events Is NOT an Example of Genocide

Which of the following events is NOT an example of genocide?

A) During the 1960s,the Cultural Revolution took place in Communist China.
B) In the late 1970s,two million Cambodians died in the Khmer Rouge's killing fields.
C) During the 1990s,in the African country of Rwanda,hundreds of thousands of the minority Tutsis were massacred by the dominant Hutu group.
D) During the 1990s,in the former Yugoslavia,Bosnian and Kosovar Muslims were summarily executed by the Serb majority.