Answer: to describe the meaning of the shell strings.
In this excerpt, the author explains to us what the meaning of the shell strings is. He tells us that the shells symbolize the union of the nations. Option B is incorrect, as the passage does not discuss anything related to the consequences of disobeying one's tribe. Option C is similarly incorrect, as the passage does not mention any of the traditions of the Lords. Finally, the passage does not explain the history of each tribe.
During the long days of summer, Karana sits on the cliff, scanning the horizon for ships. When the first storm of winter comes, she knows that no ship will come until spring. The winter storms blow onto the rock where Karana sleeps, and she is forced to move her bed to the foot of the rock. The dogs come the first night she sleeps there. She makes a fire to keep them back and kills three of them with her bow.
During the storm, Karana decides to travel across the sea to look for her people. When the storm ends, she goes to the place by the cliff where her people left their canoes (the ones they would have used to escape the Aleuts if they came back). The food in the canoes is still good, and Karana brings some water from the spring. Taking the smallest of the canoes, she leaves the island of the blue dolphins.
By dusk, her home has disappeared from sight. The sea is rough and Karana is afraid, but she uses the stars to find her way. During the night, she realizes her canoe is leaking, and plug the crack with fiber form her skirt. When dawn breaks, Karana sees she has drifted south of her planned course. She adjusts her heading, now using the sun to direct her. Soon she finds another leak, which she plugs in the same way as the last. Seeing that the planks of the canoe are weak, Karana knows that she must turn back. She is reluctant to do so, however, because the island to which she must return is so lonely and desolate. As water again starts to leak into the canoe, she turns and heads back. On her way, a swarm of dolphins begins to follow her boat. "Dolphins are a good omen," and though Karana is tired and despairing, the sight of the dolphins gives her the strength to continue. Another night passes, and Karana's canoe begins to leak, but as dawn breaks, she sees her island on the horizon. She reaches the island around noon and, forgetting the danger of the wild dogs, crawls onto the beach and falls asleep.
Karana awakes and leaves the beach the next morning, and returns to her home. Looking out over the island, she is filled with happiness. Surprised at this feeling, since only a few days earlier she had decided she could not bear to live on Ghalas-at any more, Karana knows that she will stay on the island until a ship takes her away. Because she must wait until that day, Karana decides that she must build a house and a place to store food. She scouts two possible sites for her settlement. One is near the wild dogs' cave; the other is on the headland. A third site looks good as well, but it is near the old village, and Karana does not want to be reminded of the people who once lived there.
Karana finally decides on the headland, where the sea elephants are very noisy. She begins to plan her new home, deciding that the first thing she needs is a fence to protect her food supply. It rains for the next two days, and on the third morning Karana heads toward the beach to gather materials for her new home.
