Answer:
B) It has a negative connotation, suggesting a dangerous fanaticism.
Explanation:
Martin Luther King Jr's Letter from Birmingham Jail was written during his imprisonment. He was locked up as a consequence of his and others' peaceful protests against the treatment of African-Americans in Birmingham at the time.
In the letter he refuses and condemns the violent and illegal means others might employ to defend their beliefs. For him those are the characteristics of rabid segregationists - white supremacists who supported racial separation.
As opposed to their fanatic beliefs and actions, Martin Luther King Jr refuses any law-defying action and only approves non violent protests.