Answer:
to respond to criticism
to explain the reasons for his choices
Step-by-step explanation:
King wrote the letter in response to a public statement made by eight white Alabama clergymen, who criticized King and his fellow activists for their methods of protest in Birmingham. King used the letter to respond to their criticisms and explain the rationale behind his civil rights activism, including his belief in nonviolent resistance.
There is no indication that King wrote the letter to ask for help with organizing a protest, to gain the support of other ministers, or to criticize the work of other activists.