What Happened at the 1972 Olympic Games in Munich, and Why

What happened at the 1972 Olympic Games in Munich, and why was this significant?

A) Palestinian terrorists killed Israeli athletes in an event that symbolized the
Season of discontent of the 1970s.
B) The games were canceled, signifying the resurgence of Communism in the 1970s and the most strained relations between East and West in decades.
C) The collaboration of different nationalities and ethnicities took center stage,
Indicating Germany's full return to the company of civilized nations.
D) The Red Army Faction and Red Brigades of West Germany and Italy made a
Public appearance, suggesting the prosperity of the 1970s.
E) Greece participated in the games for the first time in decades, demonstrating the restoration of democracy and sense of stability in the country.