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

<passage>:
SPACEMAN ON A SPREE BY MACK REYNOLDS Illustrated by Nodel the U.S. copyright on this publication was renewed.] What's more important—Man's conquest of space, or one spaceman's life? I bigwigs of the Department of Space Exploration as Academician Lofting before him, Si Pond would have preferred something a bit more tangible through decently. Well, possibly he didn't, given their standards. But Space Pilot Seymour Pond didn't have their standards. He'd had plenty of time to think it over. It was better to retire on a limited crediting, on a confoundedly limited crediting, than to take the two or three more trips in hopes of attaining a higher standard. He'd had plenty of time to figure it out, there alone in space on the space cafard, the madness compounded of claustrophobia, monotony, room mini-auto-apartment, complete with an autochair and built-in mini-auto-apartment ... not realizing that to a pilot it was roomy beyond belief compared to the conning tower of a space craft. was never going to subject himself to space cafard again. Just thinking "That's nonsense, Hans. Zoroaster! Either you or I would gladly take Pond's place were we capable of performing the duties for which he has been trained. There aren't two men on North America—there aren't two men in the world!—who better realize the urgency of continuing our delving into space." Gubelin snapped his fingers. "Like that, either of us would give our lives to prevent man from completely abandoning the security by being issued that minimum number of Basic shares in our clothing, shelter, medical care and education to sustain a low level dossier revealed him a possible candidate for space pilot, and it was His friend and colleague changed subjects abruptly, impatiently. "Let's leave this blistering jabber about Pond's motivation and get to the point. The man is the only trained space pilot in the world. It will take months, possibly more than a year, to bring another novitiate pilot to the point where he can safely be trusted to take our next explorer craft out. Appropriations for our expeditions have been increasingly hard to come by—even though in spark the race that a new dream to push man out to the stars will take hold of us. If it is admitted that our organization has degenerated to the point that we haven't a single pilot, then it might well be on Appropriations, will terminate the whole Department of Space Exploration." "You must realize, my dear Lofting, that our Si Pond is nothing more universal credit card. "The ultimate means of exchange," he grunted. for space pilot, he had celebrated once again. Twenty-two others had taken the training with him, and only he and Rod Cameroon had passed Each time Si returned from one of his own runs, he celebrated. A spree, in adapting to the automation of the second industrial revolution. They had attempted to give everyone work by reducing the number of unemployed, with their Inalienable Basic stock as the equivalent of Thus, Si was vaguely aware, it had always been down through the Si was going to do it differently this time. retirement-rank suit he had so recently purchased. His space pin he Attired satisfactorily, Si double-checked to see that his credit screen and said, "Balance check, please." He opened the small, closet-like door which housed his vacuum-tube two-seater, and wedged himself into the small vehicle. He brought down the canopy, dropped the pressurizer and considered the dial. Only one place really made sense. The big city. "Nothing too good for ex-Space Pilot Si Pond," he said aloud. shot, and Si took the involuntary breath from which only heroes could A voice said gently, "If the quarters are satisfactory, please present Si took his time. Not that he really needed it. It was by far the most or do much drinking in his suite. He made a mock leer. Not unless he mattress. For a moment he stood in the center of the floor, in thought. Take it around in second-class groggeries, no eating in automated luncheterias. the grand manner. No cloddy was Si Pond. "Kudos Room." At the door to the famous rendezvous of the swankiest set, Si paused a The drinks in the Kudos Room might be concocted by hand, but Si noticed dreamed about, out there in the great alone, seated in the confining conning tower of his space craft. He sipped at the drink, finding it up who occupied the stool two down from him. Si Pond blinked. He blinked Kudos Room was supposed to be exclusive." building the drink. Si cleared his throat. "Hey," he said, "how about letting this one be Oriental motif, rose. "Really!" she said, drawing it out. space pin?" Si, disconcerted by the sudden reversal, said, "Yeah ... sure." "Good Heavens, you're a spaceman?" "Sure." He pointed at the lapel pin. "You can't wear one unless you been on at least a Moon run." Si, carrying his glass, moved over to the stool next to her. "Call me Si," he said. "Everybody calls me Si." "Si," Si said, gratified. Holy Zoroaster, he'd never seen anything current sex symbols, but never in person. "Call me Si," he said again. "I been called Si so long, I don't even know who somebody's talking to him in the Space Exploration department, he was hot for it." ?" Si was expansive. "Why, sure. In the Space Department we don't have much time for formality. Everybody's just Si, and Doc, and Jim. Like your space-pilot uniform, the veteran of six exploration runs to the planets...." "Well," Si said modestly, "two of my runs were only to the Moon." "... and he said all those things about man's conquest of space. And the dream of the stars which man has held so long. And then the fact that you were the last of the space pilots. The last man in the whole world trained to pilot a space craft. And here you were, retiring." Si grunted. "Yeah. That's all part of the Doc's scheme to get me to So old man Gubelin, and Girard-Perregaux too, they're both trying to pressure me into more trips. Otherwise they got a Space Exploration Department, with all the expense and all, but nobody to pilot their ships. It's kind of funny, in a way. You know what one of those spaceships costs?" Si said, "Look, how about another drink?" "Si," Si said. He motioned to the bartender with a circular twist of in space any more. In fact, most people are almost contemptuous, like. Think it's kind of a big boondoggle deal to help use up a lot of materials and all and keep the economy going." Natalie said earnestly, "Why, I've been a space fan all my life. I've read all about it. Have always known the names of all the space pilots Si chuckled. "A real buff, eh? You know, it's kind of funny. I was after my first run and I found out what space cafard was." keeps that angle mostly hushed up and out of the magazine and newspaper articles. Says there's enough adverse publicity about space exploration already. But at this stage of the game when the whole ship's crammed tight with this automatic scientific apparatus and all, there's precious little room in the conning tower and you're the only man aboard. The Doc says later on when ships are bigger and there's a whole flock of people aboard, there won't be any such thing as space cafard,

<question>:
What is the “space cafard” that Si describes?

<options>:
A It’s the isolation that spacemen feel working alone in space, with only computers as company
B It’s the public’s adverse opinion of space exploration that Gubelin tries to hide.
C It’s the desire to return home from a long voyage.
D It is the current system of operations for spacecraft, where people man ships with only one person.

<answer>:

A