Read the following passage and questions, then choose the right answer from options, the answer should be one of A, B, C, D.

<passage>:
He looked at the planet a long time and murmured, "Venus. Pohtah." That next week, I transported all of the volplas out to the oak woods. There were a hundred and seven men, women and children. With no design on my part, they tended to segregate into groups consisting of four to Volpla By WYMAN GUIN Illustrated by DICK FRANCIS about four square miles of the ranch. They had found a new delicacy, sparrows, and hunted them easily as they roosted at night. I had taught the volplas to use the fire drill and they were already utilizing the local grasses, vines and brush to build marvelously contrived tree houses in which the young, and sometimes the adults, slept through had anesthetized all the experimental mutants, and the metabolic accelerator and other lab equipment was being dismantled. I wanted nothing around that might connect the sudden appearance of the volplas with my property. It was already apparent that it would take the volplas only a few more weeks to learn their means of survival and develop an embryonic culture of their own. Then they could leave my ranch and the fun would be on. "I've finished my work and we no longer need the buildings. I'm going to write a paper about my results." "That's what I Twenty-four hours later, there wasn't a sign of animal experimentation on the ranch. Except, of course, that the woods were full of volplas. At night, I could hear them faintly when I sat out on the terrace. As they passed through the dark overhead, they chattered and laughed and sometimes twelve. I glanced across the animal room to where old Nijinsky thrust his graying head from a cage. I had called them volplas since the day old Nijinsky's elongated arms and his cousin's lateral skin folds had given me the idea of a flying mutant. create them that I had been calling them volplas for ten years. No, Volplas at last. Three of them. Yet I had always been so sure I could the clamp. Again in the laboratory, I entered the metabolic accelerator and withdrew the intravenous needles from my first volplas. I carried their limp little forms out to a mattress in the lab, two girls and a boy. The accelerator had forced them almost to adulthood in less than a I opened a bottle of beer and guzzled from it, blew out my breath and looked across the rolling hills and oak woods of our ranch to where the Pacific shimmered. I thought, "All this and three volplas, too." I wiped the back of my hand across my mouth and said aloud, "Yes, sir, direction. . Why?" "Because, dear, I said so." for. I had aimed only at a gliding mammal a little more efficient than the Dusky Glider of Australia, a marsupial. Even in the basically mutating colony, there had been a decidedly simian appearance in recent years, a long shift from the garbage-dump rats I had started with. But my first volplas were shockingly humanoid. They were also much faster than had been their predecessors in organizing their nervous activity after the slumbrous explosion of perfectly. I strapped her ankle and pretended to use the key to tighten fur as soft as chinchilla. The faces were appealingly humanoid, except that the eyes were large and nocturnal. The cranium was in the same proportion to the body as it is in the human. Suddenly, as I teased the male volpla, this happened. The spars added nine inches on each side to his span. As they swept out and forward, the lateral skin that had, till now, hung in resting folds I sipped at my martini and lounged in a terrace chair watching the golden evening slant across the beautiful hills of our ranch. I dreamed. I would invent a euphonious set of words to match the Basic have their own crafts and live in small tree houses. I would teach them legends: that they had come from the stars, that they had subsequently watched the first red men and then the first white men enter these hills. When they were able to take care of themselves, I would turn them loose. There would be volpla colonies all up and down the Coast before anyone suspected. One day, somebody would see a volpla. The newspapers would laugh. Then someone authoritative would find a colony and observe them. He and ask, "Where have these aliens come from?" The government would reluctantly admit the facts. Linguists would observe at close quarters and learn the simple volpla language. Then would come the legends. Volpla wisdom would become a cult—and of all forms of comedy, cults, I think, are the funniest. my volplas. But only for a moment. A ball of flame appeared at the base of the rocket. Miraculously, the massive tower lifted, seemed for a moment merely to stand there on a was Africa and Europe we were looking at. The women were kissing him and hugging him. Everybody was yelling at once. I used the metabolic accelerator to cut the volplas' gestation down to one week. Then I used it to bring the infants to maturity in one month. I had luck right off. Quite by accident, the majority of the early infants were females, which sped things up considerably. By the next spring, I had a colony of over a hundred volplas and I shut down the accelerator. From now on, they could have babies in their own way. I had devised the language for them, using Basic English as my model, They kept me busy relating their words for "tree," "rock," "sky" to the Until I had them out in the open country, it had been impossible to appreciate fully what lovely little creatures they were. They blended perfectly with the California landscape. Occasionally, when they raised Chronicle motored out into the hills to witness this! Of course, the volplas didn't want to return to the lab. There was a tiny stream through there and at one point it formed a sizable pool. They got into this and splashed their long arms about and they scrubbed He came and squatted, conference fashion, the elbows resting on the ground, the wrists crossed at his chest. He spoke first. "Before the red men came, did we live here?" "You lived in places like this all along these mountains. Now there are very few of you left. Since you have been staying at my place, you naturally have forgotten the ways of living outdoors." "We can learn again. We want to stay here." His little face was so where the doves rested. I heard their mourning from the oak tree. It occurred to me they would not leave that safety while the hawklike silhouette of the volpla marred the sky so near. The birds came out of the tree, climbing hard with their graceful strokes. I looked back, as did the girl remaining beside me. The soaring volpla across the sky. The doves abruptly gave up their hard climbing and fell away with swiftly beating wings. I saw one of the male volpla's planes open a little. He veered giddily in the new direction and again dropped like a molten arrow. The doves separated and began to zigzag down the valley. The volpla did something I would not have anticipated—he opened his planes and shot lower than the bird he was after, then swept up and intercepted the bird's crossward flight. I saw the planes close momentarily. Then they opened again and the bird plummeted to a hillside. The volpla landed gently atop the hill and stood looking back at us. The volpla beside me danced up and down shrieking in a language all her own. The girl who had raised the birds from the tree volplaned back to us, yammering like a bluejay. his wonder. "You say we came from there?" "The old ones of your kind told me so. Didn't they tell you?" language, Pohtah."

<question>:
Why is the story's setting important for the plot?

<options>:
A The narrator's ranch is so big it can conceal its inhabitants.
B The volplas can only survive in California.
C There are sparrows for the volplas to eat at the narrator's ranch.
D The volplas originally lived in a similar landscape.

<answer>:

A