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

<passage>:
the vast things that had happened to himself, and to the death. But Ned Vince lived again—a million years later! "See you in half an hour, world. The scope of it all was too Ned Vince made a last effort talking about," he grated wildly. "But I want to get out of here! I want to go back where I came from! Do you understand—whoever, or whatever you are?" Loy Chuk pressed more keys. "But you can't go back to the Twentieth Century," said the box. "Nor is there any better left on Earth. Those men that exist in other star systems are not really your kind anymore, though their forefathers originated on this planet. They have gone far beyond you in evolution. To them you would be only a senseless curiosity. You are much better off with my people—our yours. We will take care of you, and make you comfortable...." hadn't yet tarred the traffic-loosened now. "You are the only man left on Earth." That had Ned could scarcely have chosen An incredible science, millions of years old, lay in the minds of these creatures. been enough for him to hear. He gravel at the Bend. didn't more than half believe it. being stranded alone on another world! His heart was pounding heavily, to escape this nameless lair, to try to learn the facts for himself, possessed him. He bounded out of the vat, and with head down, dashed for the Vince knew that his friends and his family would never see his body again, lost beyond recovery in this abyss. at last at the surface. He stood there panting in that dash-panel, leaving Ned in absolute frigid, rarefied air. It was night. after a million years of erosion under an ocean that was gone. In that ghastly moonlight, the might as well be an exile on another planet—so changed had the Earth become. A wave of intolerable homesickness came over him as he sensed the distances of time that had passed—those inconceivable eons, separating himself from his friends, from Betty, from almost dinosaurs, still bulked along the highway. Time, the Brother of Death, and the Father of Change, seemed to wait.... in his hell-world, lost beyond the barrier of the years.... presently came upon Ned Vince's unconscious form, a mile from the city of Kar-Rah. In a flying machine they took him back, and applied stimulants. He came to, in the same laboratory room as time, so that he could not escape again. There he lay, helpless, who have discovered something remarkable. The desolate expanse around until presently an idea occurred "But listen!" Ned protested. did in the Twentieth Century. And—well—there's that thing called time-travel, that I used to read about. Maybe you know how to make it work! Maybe you could send me back to my own time after all!" debris that had once been steel. A launching catapult for the last space ships built by the gods in exodus, perhaps it was—half a million years ago. Man was gone from the Earth. Glacial ages, war, decadence, disease, and a final scattering of those ultimate superhumans to newer worlds in other solar systems, had done that. So Loy considered carefully what Ned Vince had suggested. Time-travel. Almost a legend. An assault upon an intangible wall that had baffled far keener wits which seemed to depend on a blast of atoms to clear away rock and soil. Thus the gulch had been cleared of the Loy jabbed buttons on the black box. "Yes, Ned Vince," said the sonic apparatus. "Time-travel. Perhaps that is the only thing to do—to send you back to your own period of history. For I see that you will never be as ruler of the Earth. Loy Chuk had flown his geological expedition out from the Man, it seemed, had a successor, for there was real hope now, where there had been none before. Maybe he'd be back in his far lowlands to the east, out soon.... Ned relaxed, as a tiny into unconsciousness, Loy Chuk went to work once more, using that pair of brain-helmets again, exploring carefully the man's mind. After hours of research, dream and invent, and the civilization of his kind was already far beyond that of the ancient were gathered, tense and gleeful, around the things their Ned Vince's mind swam like an airtight coffin, had by now been chipped away by the tiny investigators clothing still clung to it, after perhaps a million years. Metal had gone into decay—yes. But not this body. The answer to this and change in stasis. A perfect Not the star-conquering demi-gods, but the ancestral stock that had built the first machines on Earth, and in the early Twenty-first Century, the first interplanetary rockets. No paleontological enthusiasm! A strange accident, happening in a legendary antiquity, had aided them in their quest for knowledge. Ned Vince's mind, over which of this ancient human corpse. What his probing gaze revealed devoid of moisture, the mummy was perfectly preserved, even to its brain cells! Medical and biological sciences were far advanced principles long known to them, this long-dead body could be study it would make, back there in the museums of Kar-Rah! Thus Loy Chuk's kind could now. He had wandered far out into cold, sad sea-bottom, to With infinite care—small, to himself, contemplating the magnificent, inexorable march of the ages. He remembered the ancient ruins, left by the final supermen. With infinite care it was crated in a metal case, and hauled into disengaged from the worthless there was no other way. Time is arose, bearing the entire hundred researches among the cities of the supermen show the truth. Even they, who once ruled Earth, never escaped from the present by so much as an instant...." THE END members of the expedition. an Eternal Wall. Our archeological were gone forever. Beyond the eastern rim of the had built their homes mostly underground, since the beginning of their foggy evolution. Besides, in this latter day, the nights were very cold, the shelter of subterranean passages and rooms was welcome. The mummy was taken to Loy Chuk's laboratory, a short distance below the surface. Here at once, the scientist began his work. The body of the ancient man was put in a large vat. passing between complicated electrodes. The cells of antique flesh and brain gradually took on a chemical composition nearer to that of the life that they had once known. At last the final liquid was drained away, and the mummy lay there, a mummy no more, but instruments. The time passed swiftly. For Ned Vince, timeless eternity around him. Though it had been dehydrated, his brain had been kept perfectly intact through the ages, and now it was restored. So his memories were as vivid as accumulated rubbish of antiquity. effect on Ned Vince—a sudden, Ned's gaze searched for the source of the voice—located the black box just outside of his crystal vat. From that box the sharp hand-tools were used, now—the Ned Vince did not know how Loy Chuk had probed his brain, with the aid of a pair of helmets, and the black box apparatus. He did not know that in the latter, his language, taken from his own revitalized mind, was recorded, were not human, would have had rust of his primitive automobile. great difficulty speaking English Loy's box, with its recorded English words and its sonic detectors, could translate for its the flying machine. Flashing flame, the latter things that you've got to get used to, that's all. You drowned about a million years ago. I discovered your body. I brought you back to life. We have science home," Loy was thinking. "He that can do that. I'm Loy Chuk...." will survive and be happy. But "Speaking to me. One million years. Evolution. The scientists say that people grew up from

<question>:
Why can't Loy Chuk use time travel to send Ned back to Earth before his death?

<options>:
A The government of Kar-Rah turned down Loy Chuk's request to use time travel.
B There is no such thing as time travel.
C No one has figured out time travel.
D Humans took the secrets of time travel with them when they left Earth.

<answer>:

C