I believe it is the last sentence highlighted in the paragraph.
A Long Walk to Water Summary Chapter 1
Southern Sudan, 2008
Nya is an 11-year-old girl. She goes to fetch water for her family. It will take her half the morning to get there, but this part—carrying an empty water jug—is the easy part of the journey. She will endure heat and thorns in her feet along the way.
Answer:
Reading the entire text
Explanation:
By reading the entire text, one can grab and understand the story's plot, its whole characterization, and the main conflict of the story. Hence, even if the characters and subplots change through the story, one will still be able to identify the actual theme of the story.
Therefore, the prerequisite to understanding the major or recurrent theme discussed in a text is "by reading the entire text."
I would say that the answer is to entertain because it doesn't give a topic for the short story, but it's just fiction and most fiction stories are to entertain.