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

<passage>:
They weren't human. They were something more—and something less—they were, in short, humanity's hopes for survival! Pandora creaked and groaned as her landing pads settled unevenly in the mucky surface of the ugly world outside. She seemed to be restless to end her fool's errand here, two hundred light years from the waiting hordes on Earth. Straining metal plates twanged and echoed through her hallways. but ten years of responsibility had pressed down his shoulders and put age-feigning hollows under his reddened eyes. The starlanes between Earth and her potential colonies were rough on the men who traveled them now. He shuffled toward the control room, grumbling at the heavy gravity. during the night?" "About a dozen blobs held something like a convention a little ways north of us. They broke up about an hour ago and streaked off into the clouds." The blobs were a peculiarity of this planet about which nobody knew anything. They looked like overgrown fireballs, but seemed to have an almost sentient curiosity about anything moving on the ground. "And our two cadets sneaked out again. Barker followed them, but lost them in the murk. I've kept a signal going to guide them back." Gwayne swore softly to himself. Earth couldn't turn out enough starmen in the schools, so promising kids were being shipped out for training Of course there was no obvious need for caution here. The blobs hadn't seemed dangerous, and the local animals were apparently all herbivorous something had happened to the exploration party fifteen years glowed yellow-green. Motions around them suggested a herd of feeding animals. Details were impossible to see through the haze. Even the trying to read sense into the things. If he had time to study them.... But there was no time. Earth had ordered him to detour here, after leaving his load of deep-sleep stored colonists on Official World 71, to check on any sign of Hennessy. He'd been here a week longer than he should have stayed already. If there was no sign in another day or so of what had happened to the men who'd deserted their ship and its equipment, he'd have to report back. He would have left before, if a recent landslip hadn't exposed enough of the buried ship for his metal locators to spot from the air by luck. It had obviously been hidden deep enough to foil the detectors The blobs had left the herd. Now the three were streaking at fantastic speed to a spot near the ship, to hover excitedly above something that moved there. He saw the two cadets then, heading back to the waiting ship, just beyond the movement he'd seen through the mist. confusion. But someone was taking over now—one of the crew women. The jeeps were lining up. One, at the front, was stuttering into life, and Gwayne dashed for it as the exit port slid back. There was no time for suits or helmets. The air on the planet was miles an hour now, but the horde began to increase the distance, in spite of the load of the two struggling boys! The creatures dived downward into lower ground, beginning to disappear into the mists. leave his suit the radio would have let him keep in contact with the kids. But it was too late to go back. sickly. Smoke and this air made a foul combination. "Bob, it still makes no sense. We've scoured this planet by infra-red, and there was no sign of native villages or culture. We should have found some." "Troglodytes, maybe," Gwayne guessed. "Anyhow, send for me when you get anything. I've got to get this ship back to Earth. We're overstaying our time here already." The reports from the cadets were satisfactory enough. They'd been was almost certainly spoorless by now. The only possible answer seemed to be that the exploring expedition and Hennessy's rescue group had been overcome by the aliens. It was an answer, but it left a lot of questions. How could the cunningly, and only the accidental slippage had undone their work. Maybe there would never be a full answer, but he had to find something—and find it fast. Earth needed every world she could make remotely habitable, or mankind was probably doomed to extinction. The race had blundered safely through its discovery of atomic weapons into a peace that had lasted two hundred years. It had managed to prevent an interplanetary war with the Venus colonists. It had found a drive that led to the stars, and hadn't even found intelligent life there to be dangerous on the few worlds that had cultures of their own. But forty years ago, observations from beyond the Solar System had It wouldn't be much of an explosion, as such things go—but it would render the whole Solar System uninhabitable for millenia. To survive, man had to colonize. And there were no worlds perfect for him, as Earth had been. The explorers went out in desperation to find what they could the terraforming teams did what they could. And then the big starships began filling worlds with colonists, carried in deep sleep to conserve space. Almost eighty worlds. The nearest a four month journey from Earth and four more months back. In another ten years, the sun would explode, leaving man only on the footholds he was trying to dig among other solar systems. Maybe some of the strange worlds would let men spread his seed again. Maybe none would be spawning grounds for mankind in spite of the efforts. Each was precious as a haven for the race. If this world could be used, it would be nearer than most. If not, as it now seemed, no more time could be wasted here. Primitives could be overcome, maybe. It would be ruthless and unfair to squatting in the clearing fog, holding lances and staring at the ship. They were perhaps a thousand yards away, waiting patiently. For what? For the return of their leader—or for something that would give the ship to them? as the great tanks of fuel discharged their contents out onto the ground where no ingenuity could ever recover it to bring life to the ship again. all life here had twelve legs. Now they're changing that, as we've seen. "And they don't have to be close to do it. We've all been outside the hull. It doesn't show yet—but we're changed. In another month, Earth food would kill us. We've got to stay here. We'll bury the ships deeper this time, and Earth won't find us. They can't risk trying a colony where three ships vanish, so we'll just disappear. And they'll never know." Nobody would know. Their children—odd children who matured in eight years—would be primitive savages in three generations. The Earth tools would be useless, impossible for the hands so radically changed. Nothing from the ship would last. Books could never be read by the new same answer he had found for himself. "The spawning ground!" It was the only thing they could do. Earth needed a place to plant her seed, but no world other than Earth could ever be trusted to preserve that seed for generation after generation. Some worlds already were becoming uncertain. Here, though, the blobs had adapted men to the alien world instead of men having to adapt the whole planet to their needs. Here, the strange children of man's race could grow, develop and begin the long trek back as rich a set of bloodlines as possible to give the new race strength. The fifty men and women on this ship will be needed to start them with a decent chance. We can't go to Earth, where nobody would believe or accept the idea—or even let us come back. We have to stay here." earth." "No," he told her. "Replenish the stars." But she was no longer listening, and that part of his idea could wait. Some day, though, their children would find a way to the starlanes again, looking for other worlds. With the blobs to help them, they could adapt to most worlds. The unchanged spirit would lead them through all space, and the changing bodies would claim worlds beyond numbering. Some day, the whole universe would be a spawning ground for the

<question>:
Why was space exploration so important?

<options>:
A it was trendy to live on a different planet
B there was a lot of interest in life on other planets
C they were running out of time on Earth
D people were trying to leave the wars on Earth

<answer>:

C