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

<passage>:
Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] The most dangerous is not the outlawed murderer, who only slays men, but the rebellious philosopher: for he destroys worlds. catfooting too softly to set up vibrations. A man could do that when gravity was feeble enough. Bo Jonsson looked at the wrench in his hand. It was long and massive, the stars and reset the machinery of a universe gone awry. He smiled stiffly at the thought. He wanted to laugh too, but checked himself for had to be a hunter, too, and track down the other man, before he died. command. But he couldn't do that. Even if the other man let him do it, spaceships need not waste fuel coming up to a body which has been perturbed a goodly distance from where it was supposed while minimizing the effects of Jupiter's drag. so that Achilles among the leaders and Patroclus in the trailers have a permanent boom town atmosphere. Even though a spaceship and equipment represent a large investment, this is one of the last strongholds of rockhound dreaming of the day when his stake is big enough for him to start out on his own—a race of individualists, rough and noisy and jealous, but living under iron rules of hospitality and rescue. The Last Chance on Achilles has another name, which simply sticks an "r" in the official one Bo Jonsson into going there for a final spree before checkoff and he didn't grate on Bo, they had been partners for several years now. miracle found an empty booth. Bo squeezed his bulk into one side of the drinks. Bo was larger and heavier than most spacemen—he'd never have whiskey and charge for!" "Everything's expensive here," said Bo mildly. "That's why so few rockhounds get rich. They make a lot of money, but they have to spend it just as fast to stay alive." think the eminent Dr. McKittrick is gonna be interested in sociability, and it's close quarters aboard the Dog "Because I am one at heart. Look, Bo, why don't you get over that inferiority complex of yours? A man can't run a spaceship without knowing more math and physical science than the average professor on Mozart through a horn. So what?" Johnny's head darted around, birdlike. "If we want some women we'd better make our reservations now." "I don't, Johnny," said Bo. "I'll just nurse a beer." It wasn't morals so much as fastidiousness he'd wait till they hit Luna. "Suit yourself. If you don't want to uphold the honor of the Sirius Transportation Company—" Bo chuckled. The Company consisted of (a) the (b) her crew, back in Luna City. Not exactly a tramp ship, because you can't normally but she went wherever there was cargo or people to be moved. Bo shook his head and watched his partner move off, swift in the puny Bo sighed, feeling a bit lonesome. If he wasn't going to make a night of it, there was no point in drinking heavily. He had to make the final he'd been on Earth! Johnny made some reply. Bo heaved up his form and strode toward the only clear thought which ran in the sudden storm of Bo's head. next face of the rough cube which was the asteroid. Bo lay on his belly much of an impetus to throw him off this rock entirely. Then his helpless and soon frozen body would be just another meteor for the next Bo stood unmoving an instant, fighting the impulse to leap away. He was a spaceman, not a rockhound he wasn't used to this environment, and if he jumped high he could be riddled as he fell slowly down again. Sweat Theoretically, one man can run a spaceship, but in practice two or three are required for non-military craft. This is not only an emergency reserve, but a preventive of emergencies, for one man alone might get too tired at the critical moments. Bo knew he wouldn't be allowed to leave Achilles without a certified partner, and unemployed spacemen available for immediate hiring are found once in a Venusian snowfall. Bo didn't care the first day. He had taken Johnny out to Helmet Hill to space, Johnny was the last Bo returned to the transient quarters and dialed Valeria McKittrick. "Hadn't you heard?" asked Bo. He found it hard to believe she could "Johnny's dead. We can't leave." clear brow. "But you've got to get me back. I've engaged passage to Luna with you." "Your ticket will be refunded, of course," said Bo heavily. "But you aren't certified, and the Sirius is licensed for no less than two operators." "Well ... damn! There won't be another berth for weeks, and I've got to get home. Can't you find somebody?" Bo shrugged, not caring much. "I'll circulate an ad if you want, but—" "Do so, please. Let me know." She switched off. Achilles for about a year working on some special project and was now ready to go home. She was human enough, had been to most of the officers' parties and danced and laughed and flirted mildly, but even the dullest rockhound was rare, and a virtuous woman unheard-of as a result, unknown to Since coming here, on commission from the Lunar lab, to bring her home, Bo Jonsson had given her an occasional wistful thought. He liked intelligent women, and he was getting tired of rootlessness. But of course it would be a catastrophe if he fell in love with her because she wouldn't look twice at a big dumb slob like him. He had sweated out a couple of similar affairs in the past and didn't want to go through another. He woke up many hours later. Achilles ran on Earth time but did not here too for the next several months." "How does a qualified spaceman happen to be marooned?" Bo nodded, for every spaceman knows exactly what every spaceship is gasket. Why the accident should have occurred, nobody knew ... spacemen Bo had heard of it in the course of "I thought she went back anyway," he said. Lundgard nodded. "She did. It was the usual question of economics. also, the delay while we got it would have carried Earth and Achilles past optimum position, which'd make the trip home that much more expensive. Since we had one more man aboard than really required, it was cheaper to leave the difference in mass would make up for the fuel loss. I volunteered, even suggested the idea, because ... well, it happened during my watch, and even if nobody blamed me I couldn't help feeling guilty." Bo understood that kind of loyalty. You couldn't travel space without men who had it. "The Company beamed a message: I'd stay here till their schedule permitted an undermanned ship to come by, but that wouldn't be for maybe months," went on Lundgard. "I can't see sitting on this lump that long without so much as a chance at planetfall bonus. If you'll take me on, I'm sure the Company will agree I'll get a message to them on the "Take us a while to get back," warned Bo. "We're going to stop off at no other ship was leaving immediately. They fed it the data and Bo went at his share of the job doggedly, checking and re-checking her three passengers up to her orbit, they embarked, settled down, and Bo relaxed against the thrust, thinking of Achilles falling away behind Bo clamped his teeth together, as if he would grip consciousness in Bo's mind wavered back toward life. He opened the valves wide on his to lie on naked rock while the enemy hunted him. Bo shuddered and

<question>:
Why would Bo not be allowed to take a ship back to Earth by himself?

<options>:
A The job is simply too big for one person, as it takes multiple people to perform the necessary functions of the ship.
B He can, as it technically only takes one person to pilot a ship back to Earth.
C It is a safety issue.
D It is against regulations because they do not want the loan person to go insane due to a lack of companionship.

<answer>:

C