Levers don't have a lot of moving parts, so they don't generate as much friction as other machines do.
Answer: Activist?
Explanation: sorry if wrong
B. Orval Faubus, the governor of Arkansas, refused to allow nine African American students to enroll in Little Rock Central High School.
C. President Kennedy was persuaded by Martin Luther King's "I Have a Dream" speech.
D. The Supreme Court refused to order all public schools to desegregate as quickly as possible.