Answer:
B. “Neither should it ever happen that once more the avenues to peaceful change are blocked by usurpers who seek to take power away from the people, in pursuit of their own, ignoble purposes.” (Paragraph 27)
Explanation:
This question refers to Nelson Mandela's Nobel Peace Prize Lecture given in 1993.
His speech, although dealing with racial issues in South Africa, quickly expanded to world-wide problems, such as war, violence, poverty, racism. He used his speech as a platform to call for peaceful acts throughout the world.
This purpose of his speech can best be inferred from answer B. where he hopes that never again power seeking, immoral individuals will block the way to peaceful changes and prosperity.