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

<passage>:
to logic. "Living space, for one thing. The only permanent solution to the population problem...." "We have no population problem. A hundred years ago, we realized that the key to social stability is a limited population. Our economic I have been saying applies to most of the world. In some places like ocean pushed into waves by the breeze stretching to the horizon. This wasn't the California desert! Down the hill, where the liquid oxygen plant ought to have been, a river wound across the scene, almost hidden there and walk under a new sky and a smaller Sun? Aren't you interested in finding out what the canals are? Or what's under the clouds of Venus? Wouldn't you like to see the rings of Saturn from, a distance of only two hundred thousand miles?" His hands were trembling as he beneath its leafy roof of huge ancient trees. stopped. your blood, the idea of going to Mars—just to go there and see what's Where was he? Who had brought him here? For what purpose? a member of the original atomic reaction-motor team, he possessed She smiled. "In a room downstairs there is the head of a lion. Swarts traveling is the greatest adventure there is. At least, that is the way I feel. Listen, Bob." She laid a hand on his arm. "You grew up in "Because this is the Age of Man . We are terribly interested in what can be done with people. Our scientists, like Swarts, are studying a discouraging analogy. His present position was like that of an earnest 12th Century crusader, deposited by some freak of nature into hadn't heard of. Security sometimes had disadvantages. He looked out at the peaceful vista of river and prairie. The character This man was intelligent, Maitland decided, and extremely sure of Impassively, the man said, "My name is Swarts. You want to know where to protest, but Swarts went on, "However, you're free to do all the Briefly, then, Swarts did smile. "They won't find you," he said. "Now, After that outlandish cell, Swarts' laboratory looked rather "What's the idea?" Maitland asked. "What is all this?" Swarts hesitated, though not, Maitland astonishedly felt, to evade an If Swarts was irritated, he didn't show it. "That was the first test," "I see," Swarts said. "You want to find out what you're up against." his chest, hips, knees, ankles, and arms, and Swarts was tightening a So—Maitland thought—Swarts could record changes in his skin "Your name," said Swarts, "is Robert Lee Maitland. You are thirty-four question you about your work just forget about it. Your home town is Madison, Wisconsin...." "You seem to know everything about me," Maitland said defiantly, "I do not know everything about you—yet. And I'm testing the equipment, calibrating it to your reactions." He went on, "Your favorite recreations are chess and reading what you term science fiction. Maitland, how would you like to go to the Moon Swarts was chuckling. "I really hit a semantic push-button there, didn't I? Maitland, I brought you here because you're a man who wants to go to the Moon. I'm interested in finding out why ." She was looking at him with palpable curiosity and something like There were three questions for which he required answers before he could formulate any plan or policy. Where was he? Who was Swarts? What was the purpose of the "tests" he was being given? for getting military secrets, despite Swarts' protestations to the foreign intelligence officers. It might be better to tackle the first question first. He looked at the Sun, a red spheroid already half below the horizon, and tried to think of a region that had this kind of terrain. That prairie out there was unique. Almost anywhere in the world, land like that would be cultivated, not allowed to go to grass. This might be somewhere in Africa.... He shook his head, puzzled. The Sun disappeared and its blood-hued peace and an undefinable longing. Venus, the most beautiful of the planets. Maitland kept track of them all in their majestic paths through the constellations, but Venus was his favorite. Time and time again he had watched its steady climb higher and higher in the western sky, have to worry any more about military secrets, or who Swarts was. way of breaking down Swarts' reticence. He would have to make the man realize that secrecy wasn't necessary in this case. And if Swarts still shoulder, "You will have to ask Swarts about that. I cannot tell you." Swarts came half an hour later, and Maitland began his planned offensive. "What year is this?" Swarts' steely eyes locked with his. "You know what the date is," he "Come on," Swarts said patiently, "let's get going. We have a lot to the instruments, making no resistance at all. When Swarts started tracing back of steps. After several minutes, he noticed that Swarts It took Swarts nearly twenty minutes to set up the new apparatus. He He thought of a fat slob of a bully who had beaten him up one day Swarts in standing by his silly rules and not telling him about this forehead, and he began to curse. Swarts! How he hated.... eyes and Swarts was standing over him, white-lipped. Maitland swore at "All right," Swarts said. "A.D. 2634." "I really haven't the time to waste talking irrelevancies," Swarts said Maitland considered a moment, then nodded. Swarts lowered the projector aboard a ship dropping in toward Mars, making planetfall at Syrtis Major he was seeing visions of Venus and the awesome beauty of Saturn. In his mind, he circled the Moon, and viewed the Earth as a huge bright globe against the constellations.... want, even from Swarts, and I have not been able to get even a little Eagerly he asked, "Why the devil do you want to go to the 20th Century? She shrugged. "Swarts says that I want to go back to the Dark Age of culture? Don't tell me you're "Oh, no! But my home is Aresund, a little fishing village at the head of a fiord in what you would call Norway. So far north, we are much behind the times. We live in the old way, from the sea, speak the old tongue." Oriental and European characteristics, and hesitantly asked, "Maybe I shouldn't.... This is a little personal, but ... you don't look altogether like the Norwegians of my time." His fear that she would be offended proved to be completely unjustified. She merely laughed and said, "There has been much history since 1950. Five hundred years ago, Europe was overrun by Pan-Orientals. Today you could not find anywhere a 'pure' European or Asiatic." She giggled. "Swarts' ancestors from your time must be "The South Africans." Something strange came into her eyes. It might have been awe, or even hatred he could not tell. "The Pan-Orientals eventually conquered all the world, except for North America—the last remnant of the American World Empire—and southern Africa. The "I always thought that would be a tough problem to crack," he agreed. "But tell me about what men are doing in the Solar System. How is life on Mars and Venus, and how long does it take to get to those places?" He waited, expectantly silent, but she only looked puzzled. "I don't understand. Mars? What are Mars?" After several seconds, Maitland swallowed. Something seemed to be the matter with his throat, making it difficult for him to speak. "Surely you have space travel?" She frowned and shook her head. "What does that mean—space travel?" He was gripping the edge of the bed now, glaring at her. "A arms as if to shield her face if he should hit her. "Let's get this perfectly clear," he said, more harshly than he realized. "So far as you know, no one has ever visited the planets, and no one wants to. Is that right?"

<question>:
What was Swarts interested in studying in his laboratory?

<options>:
A time travel
B human nature
C space travel
D geography

<answer>:

B