That would be the stage directions. Stage directions are usually in brackets. You can also tell because it’s give the character directions on what do physically
They are scared to go and see the doctors.
The correct answer is B.
The purpose for including this excerpt in Dr. Martin Luther King’s “Letter from Birmingham Jail” is to belittle the importance of his critic's letter.
During his time, Martin Luther King was greatly criticized for the work he was doing. However, King was known to be a peaceful and quiet man that did not pay attention to threats and critics, because they were not helpful or constructive. For him, this letters only distracted him from the work that had to be done.