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

<passage>:
one thing he could bring back from the wonderful future ... and though he didn't want to ... nevertheless he did.... Arth closed his eyes in pain. "Vegetarian," he said. "Couldn't possibly eat meat. Barbarous. Ugh." "Well, we need some nourishment," ox." "Providence," Simon told her "Lost track," Arth said. "You can Simon said, mournful of tone, come home with me." "Money," Simon said. "When you that appealed to you." "Hm-m-m. I didn't know most sleuthing amounted to snooping around department stores to check on the window and fumbled around for Simon said, enigmatically, "Now a blind or curtain. There was none. couldn't stand the light. "Where's the shade," I moaned. Arth did something and the window went opaque. "That's quite a gadget," I groaned. Simon said unenthusiastically, "If I didn't feel so lousy, I'd "You didn't have a hotel. What a stupidity. I'll be phased. Phased all the way down." "You haven't got a handful of in the phone book says you'll investigate anything." erect and heading for what "Anything," Simon said. "Only one exception." undoubtedly was a bathroom. "Stay where you are. Don't move. Don't touch anything." "Excellent. Do you believe in time travel?" Simon continued to say nothing she ventured, "Time travel is impossible." "Why?" "Why?" "All right," I told him plaintively. "I'm clean. I won't mess up the seat, Betty cleared her throat. When definite answer. She said, "Well, for one thing, paradox. Suppose you had a time machine and traveled back a hundred years or so and killed your own great-grandfather. Then how could you ever be born?" "Confound it if I know," the little fellow growled. "How?" Simon said, "Let's get to the point, some time travelers," the old boy said. Betty was too far in now to maintain her proper role of silent secretary. "Time travelers," she said, not very intelligently. The potential client sat more erect, obviously with intent to hold the floor for a time. He removed the pince-nez glasses and pointed them "Then you'll realize that there are a dozen explanations of the paradoxes of time travel. Every writer in the field worth his salt has explained them away. But to get on. It's my of immortality and eternal youth, and it's also my suspicion that he will eventually be able to travel in time. So convinced am I of these possibilities that I am willing to gamble a portion of my fortune to investigate the presence in our era of such time travelers." Simon seemed incapable of carrying the ball this morning, so Betty said, "But ... Mr. Oyster, if the future has developed time travel why don't we ever meet such travelers?" Simon put in a word. "The usual explanation, Betty, is that they can't afford to allow the space-time continuum track to be altered. If, say, a time traveler returned to a period of twenty-five years ago and shot Hitler, then all subsequent history would be changed. In that case, the time traveler himself might never be born. They have to tread mighty carefully." make heads nor tails of the check receipt. He didn't speak English and my high school German was inadequate, Simon shrugged and fumbled Mr. Oyster was pleased. "I didn't blockbusting hangover. and—" Simon held up a hand. "There's no use prolonging this. As I understand nobody should drink realize that thus far nobody has succeeded in taking it with him." with a considerable fortune and you their perch, bug-eyed Simon, but then Simon said, "You want to hire me to find a time traveler and in some manner or other—any manner will do—exhort from him the secret of eternal life and youth, which you figure the future will have discovered. You're willing to pony up a part of this fortune of yours, if I can deliver a bona fide time traveler." "Right!" date or some such. But they fixed they're interested in keeping hid?" The old boy was the center again. "I told you I'd been considering it of hours. Not only wasn't the bag Oktoberfest , that's where they'd be!" He seemed elated. he had been occupying four—or was it five—days before when I'd left. the attendant there evidently couldn't I'd lost track of the time. at the luggage checking station, but the calendar. Mr. Oyster was saying something to the effect that if I didn't leave today, it would have to be tomorrow, that he hadn't ponied up that thousand dollars advance for anything less than immediate service. Stuffing his receipt in his wallet, he fussed his way out the door. you haven't changed this calendar "All right," Simon said. "We'll accept in." She added, irrelevantly, "Time travelers yet." I tried just once more. "Uh, when Oktoberfest . For one thing, a time traveler wouldn't be conspicuous. At a festival like this somebody with a strange accent, or who didn't know exactly how to wear his clothes correctly, or was off the ordinary in any of a dozen other ways, wouldn't be noticed. You could be a four-armed space traveler from Mars, and you still wouldn't be conspicuous at the Oktoberfest . People would figure they had D.T.'s." "But why would a time traveler want to go to a—" Betty began. "Why not! What better opportunity Simon's story), "did you Simon shrugged, put one hand to of Dionysus, or one of Alexander's orgies. You wouldn't want to wander up and down the streets of, say, Athens while nothing was going on, particularly when you might be revealed as a suspicious character not being able to speak the language, not knowing how to wear the clothes and He took a deep breath. "No ma'am, you'd have to stick to some great event, both for the sake of actual interest and for protection against being unmasked." Simon winced at the noise, took Simon was shaking his head. "Not "I did," Simon groaned. "Three Simon nodded, miserably. Simon risk a considerable portion of my "Sorry," Simon said. "Can't be fortune—" time traveler, there might have been—" "I keep telling you," Simon said Probably thousands." He took a deep breath. "Listen, we're just going to have to forget about it. They're not going to stand for the space-time continuum track being altered. If something comes up that looks like you bring me a time traveler." it might result in the track being "Out of the question," Simon said. "But can't allow anything to come back from the future and change the "Just for laughs," Simon told the past." you—all over again. They just changed, they set you right back at why Simon said wearily, "There's just on top of that!" He shuddered. "If you think I'm going to take another crack at this again." THE END Transcriber's Note: give him some kind of report for his money. Time travel yet! What a laugh! Simon, said finally, "You know ponied up all the money for such expenditures? How could the average German, with his twenty-five dollars a week salary? down, pocketed the husky bribe, showed me where I could check my bag, told me they'd do what they Simon said nothing. Across the over to us and then hustled on. I skipped it. didn't seem to hang together very well. "My pilgrimage," he told me. "All Name is Simon." "No go," Simon said, a sad quality in his voice. "A fifty thousand dollar bonus if

<question>:
Why does Simon not bring back a time traveler?

<options>:
A He knows that Arth is Mr. Oyster setting a trap to ensnare Simon, who is a time traveler himself
B Simon is a time traveler himself, and would never reveal the secrets of his fellow time travelers
C He became too intoxicated with Arth and sabotaged his own investigation
D The authorities would not allow him to do anything that might significantly change the space-time continuum

<answer>:

D