Answer:
B. In contrast
Step-by-step explanation:
The first sentence shows what was popular among the many people who partook in the Civil Rights Movement in the 1960's. Many of them chose the safe path because the agitation was a volatile one that could provoke attacks from the White community.
Unlike these other people, Ali did not preach American values but freedom and equality. This shows that there was a contrast or difference between Ali and the others who engaged in the Civil Rights Movement.