The correct answer is:
A response to A Call for Unity, the statement by eight white Alabama clergymen against King and his nonviolent methods.
From the Birmingham jail, where he was imprisoned as a participant in nonviolent demonstrations against segregation, Dr. Martin Luther King, Jr., wrote the "Letter from Birmingham Jail".
It was his response to a public statement of concern and caution issued by eight white religious leaders of the South who accused King of agitating local residents and not giving the incoming mayor a chance to make any changes.