Answer:
a) One way that the killing of Jewish people during the Holocaust fits the author's definition of genocide is that the Holocaust was against groups "of an ethnic, racial, religious or national group".
b) An example of a genocide outside of the author's example is The Bosnian Genocide. This genocide followed the breakup of Yugoslavia. It meets the authors definition of genocide because Serbians tried to exterminate Bosnian Muslims, which were a minority.
c) One mass killing that is not a genocide according to the author's definition is the Black Plague. The Black Plague killed a massive amount of people, but the authors definition says "deliberate and systematic destruction", the Black Plague wasn't deliberate, it was a virus that was spread non-intentionally.