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

<passage>:
their hardships. But the future brings a new grudge—when pioneers stay put and scholars do the exploring! The very young man sat on the edge of the sofa and looked nervous. He carefully studied his fingernails and ran his hands through his hair and picked imaginary lint off the upholstery. be staffed by couples. That is, of course, as soon as it's practical." Chapman stared at the radio key. Three years on the Moon and they thought he'd be glad to stay for more. you couldn't take a shower, couldn't brush your teeth, and your kidneys didn't work right. And for double his salary they thought he'd be glad to stay for another fit of bureaucratic rage. Chapman stuffed a rag under it and ignored it. He turned to the hammocks, strung against the bulkhead on the other "They wanted me to stay until the next relief ship lands," Chapman man to stay on the job a while longer." " All they're trying to do," Chapman said sarcastically. "They've got and walked noiselessly over to the small electric stove. It was his day for breakfast duty. day of work on the Moon. In a few hours they'd be relieved by members A hundred yards from the research bunker he could make out the small mound of stones and the forlorn homemade cross, jury-rigged out of That's what happened to guys like Dixon, Chapman thought. On the Moon, have, but I think I know what you mean." He warmed up to it as the idea sank in. "Just what the hell "Nothing very spectacular," Chapman said, smiling. "I'm going to rent Chapman grinned. "Oh, just somebody. What are you going to do, Dick?" The phonograph was a small, wind-up model that Chapman had smuggled in They ran through it twice. They were beginning to feel it now, Chapman without you on it. Why, we'll look at it when we're out spooning or something and it just won't have the same old appeal." "Like they say in the army," Bening said, "you never had it so good. of rock that he wanted a sample of and some strata he wished to investigate. Chapman stopped them at the lock. "Remember to check your suits for "And I'd check you five hundred more," Chapman said. "It takes only that your little boys can watch out for themselves!" But he checked his suit for leaks and tested the valve of his tank Only Klein and Chapman were left in the bunker. Klein was at the work "Settle down in a small cottage and raise lots of little Chapmans, eh?" Chapman nodded. He put away the box and came over to the port. Chapman moved over so "Yes. It worked fine, too. We heard everything that went through his mind at the end." Klein's face was blank. "What's your real job here, Chap? Why does have to know where things are, how things work, what to watch out for. And then, because you've been here a year and a half and know the themselves. The Moon's a new environment and you have to learn how to "I suppose you could call it that." Klein said, "You're not a scientist, are you?" "No, you should know that. I came as the pilot of the first ship. We made the bunker out of parts of the ship so there wasn't anything to go back on. I'm a good mechanic and I made myself useful with the machinery. When it occurred to us that somebody was going to have to stay over, I volunteered. I thought the others were so important that it was better they should take their samples and data back to Earth Chapman frowned. "Frankly, I hadn't thought of that. I don't believe volunteered for it. I think I was fair in explaining all about the job when you talked it over among yourselves." "You did, but I don't think Dahl's the man for it. He's too young, too much of a kid. He volunteered because he thought it made him look like a hero. He doesn't have the judgment that an older man would have. That you have." "I'm not the indispensable man," he said slowly, "and even if I was, it wouldn't make any difference to me. I'm sorry if Dahl is young. So was I. I've lost three years up here. And I don't intend to lose any more." know how much you hate it and the time you put in up here. It's just—" His voice trailed away. "It's just that I think it's such a damn important job." its meager belongings to the bag. He hadn't actually needed to pack, of course. In less than twenty-four inherited from—who was it? Driesbach?—of the First group. Dahl could probably use them or maybe one of the boys in the Third. steel of the bulkhead beside his hammock. Just a few hours ago, when he woke up, he had made the last check mark and signed his name and the to the Moon. He was fumbling it badly, Chapman thought. the only one who was qualified!" Dahl looked as though he was going to be sick. Chapman tried to recall all he knew about him. Dahl, Robert. Good mathematician. Graduate from one of the Ivy League schools. Father was a manufacturer of stoves or something. It still didn't add, not quite. "You know I don't like it here any more too. What made you think I would change my mind?" Dahl took the plunge. "Well, you see," he started eagerly, too far gone to remember such a thing as pride, "you know my father's pretty well Chapman felt tired. The good feeling he had about going home was slowly all three started for the lock. Chapman was standing in front of it. "Check your suits," he said softly. "Just be sure to check." They were in the lock and the air pumped in and then they were in the bunker, taking off their suits. The newcomers were impressed and solemn, very much aware of the tremendous responsibility that rested on their shoulders. Like Donley and Klein and the members of the Second group had been when they had landed. Like Chapman had been in the First. Donley and the others were all over them. How was it back on Earth? Who had won the series? Was so-and-so still teaching at the university? What was the international situation? Chapman had gone through it all before. But was Ginny still Ginny? Chapman cut off a single blade with his fingernail and put it between Chapman sympathized. If he had had any sense, he'd have tried to smuggle something like that up to the Moon instead of his phonograph. One of the men separated from the group and came over to Chapman. He held out his hand and said, "My name's Eberlein. Captain of the relief ship. I understand you're in charge here?" Chapman nodded and shook hands. They hadn't had a captain on the First ship. Just a pilot and crew. Eberlein looked every inch a captain, too. Craggy face, gray hair, the firm chin of a man who was sure of himself. "You might say I'm in charge here," Chapman said. "Well, look, Mr. Chapman, is there any place where we can talk together at Chapman. Chapman jerked a thumb toward Dahl. "Ask him. He's in charge now." . They're working on unmanned, open-side rockets Chapman nodded. "They could use a little privacy up here." add more bunkers and have more men up here, that a man of practical experience should be running things. They figure that you're the only man who's capable and who's had the experience." The captain vaguely felt the approach was all wrong. "Is that all?" Eberlein was ill at ease. "Naturally you'd be paid well. I don't imagine any man would like being here all the time. They're prepared to double your salary—maybe even a bonus in addition—and let you have "The answer is no," Chapman said. "I'm not interested in more money

<question>:
What makes Chapman so qualified to train crews on the moon?

<options>:
A His attention to scientific details
B His technical skills and leadership
C His lack of ties back home on Earth
D His mechanical background and military training

<answer>:

B