A). To establish historical precedent for his actions.
Explanation:
Allusion exemplifies the direct and concise reference to a thing, place or person that carries cultural, historical, political or literary importance and often suggests an implied sense. King wrote several letters from Birmingham Jail and alludes to different people and places with an intended message. In this excerpt also from "Letter from Birmingham Jail”. King employs allusion to 'Boston Tea Party' in order to establish the historical criterion to the readers and symbolize the significant and enormous act of civil disobedience. Thus, the answer is option A.
ok so first let's discuss what is an allusion an allusion is an expression designed to call something to mind without mentioning explicitly, so basically for example quoting a movie
so in the situation Dr. King is in hes in Jail trynna motivate the ppl to rise up, and he mentions the Boston tea party because it was against the law BUT the right thing to do because of the taxation