The correct answer to this open question is the following.
Martin Luther King brings up examples of violence in the United States at the beginning of the speech to show that the fight for freedom from oppression is not over.
We are referring to the acceptance speech when Martin Luther King received the Nobel Peace Prize on December 10, 1964. in the city of Oslo, Norway. He gained the Prize for its permanent support and activism on civil rights and fight oppression and segregation in a nonviolent way. He was 35 years old when he received the prize, making him the youngest man to receive it.