What is meant by “the essential explanation of war”

Read the excerpt from black boy wright uses this personal experience to establish

Which of the following sentences most clearly uses topical organization? a. do you have problems with mosquitoes and gnats? fabulous exterminators can ! b. we've gathered at this conference to discuss three things: poverty, war, and disease. c. killer bees have spread up from south america into mexico and the united states. d. first, gather all the painting supplies you need. next, lay them out on a work bench.

Why did the author include the fact that 40,000 african americans participated in the bus boycott