I believe the correct answer is the last one - to provide a contrast to his group's nonviolent efforts.
Martin Luther King advocated protests, but those which didn't end up in violence. He wanted to fight for equal black rights, without having to resort to aggression and crime. Thus he added these sentence to distinguish his group from those such as Black Panther Party, and others.
Explanation:
Subtle use of alliteration= A
Strong use of alliteration=B, C, D
the right way? You start out with
Dear (Name and last name here)
(Then you go to the next line and write what you want to write here) How are you? How was your day?
(you go to the next line and write your name) From Catistic
This is how I write letters and emails.