Dr. Martin Luther King Jr.’s role as leader of the Civil Rights Movement ... ...

Dr. Martin Luther King Jr.’s role as leader of the Civil Rights Movement made him the target of violence; a flaming brick thrown through the window of his home, for example, was a __________ of greater violence, culminating in his assassination.
(A)    prologue
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Nova Sentence Equlvalence: Lesson Set