All of the following statements accurately characterize the civil rights movement between 1940 and 1970 except

• A. More and more activists advocated the use of violence after the mid-1960s
• B. Martin Luther King Jr. served as the movement’s unofficial leader from 1955 until his assassination
• C. The first major civil rights victories for black Americans were achieved in the courtroom
• D. The failure of the sit-in tactic effectively ended the civil rights movement