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

<passage>:
thousand, but he never could reach the end of it and thread its side and let the wind spin the propellers was pointless. west. The huge wheels twisted and jolted against the rocks outside, sort of aircraft could he be flying that would require an hour to cover eighty kilometers, with the wind? Heemskerk could only draw the conclusion that the aircraft had that was not the roughness of the terrain. Through the thick X minus twelve. In two minutes, it would be time for him to walk life is to be saved. He must get seven minutes the backward count before blastoff would start over the area loudspeakers. Heemskerk shook his head sadly. to Earth at once." And Van Artevelde had promised up, and we had no way to get It was a high thin whine borne on the wind, carrying even through the walls of his spacehelmet, that attracted Heemskerk's attention and caused him to pause with his foot on the him to Oostpoort." sky, trying to pinpoint the noise. Heemskerk looked westward. At first he could see nothing, Earthward orbit in a few hours. It was near the dusk of the 485-hour Venerian day, and the Twilight Gale already had arisen, sticking up from its deck in front of them. forcing his voice through the helmet diaphragm and rushing over to his friend. "I was afraid you "What's that? I didn't know there was another colony within two thousand kilometers." "It isn't a colony, in the sense Oostpoort is," explained Dekker. were lost!" bunch of laborers left behind when the colony folded several years ago. It's about eighty kilometers away, right across the Hoorn, but they don't have any damned thing ought to get here from Rathole faster than that." what happened? Even that vehicles that can navigate when to hurry for blastoff. But, first, could not support the tremendous expense of sending the boy across the millions of miles to Earth by spaceship. "Who's paying his passage?" to wait for the next ship," he has to blast off in thirty hours to catch Earth at the right orbital spot, and the G-boat has to blast off in ten hours to catch the pronounced. "The was left after it came over the western mountain. Over the Vanderdecken "or I'd have come in one of those in the first place instead of trying to cross Den Hoorn by "I'm afraid not," said Sanchez. "Too bad. There's nothing we can do, then. The nearest settlement west of here is more than a thousand kilometers away, and I happen to know they have no planes, either. Just copters. So He had little difficulty driving up and over the mountain, for the Dutch settlers had carved a rough road through the ravines. But even the 2½-meter wheels of the groundcar had trouble amid constant danger of its being flipped over by a gust if not handled easier, but he was obviously lucky, at that. Often he had to detour far from his course to The groundcar zig-zagged slowly westward. The tattered low above it, but the wind was as dry as the breath of an oven. Despite the heavy cloud cover, to have dropped to 40 degrees Centigrade in the west wind, and it was still going down. Jan reached the edge of a crack that made further progress seem impossible. A hundred meters wide, of unknown depth, it stretched out of sight in both directions. For the first time he entertained serious doubts that Den Hoorn could be crossed by land. and raced along the edge of the chasm as fast as the car would negotiate the terrain. He looked anxiously at his watch. Nearly three hours had passed since he left Oostpoort. He had seven hours to go and he was still at least 16 kilometers from Rathole. His pipe was out, but he could not take his hands from the wheel to refill it. He had driven at least eight kilometers before he realized that the crack was narrowing. At least as far again, the two edges came together, but not at the same level. A sheer cliff three meters high now barred his passage. He drove on. Apparently it was the result turned back southwestward. He made it just in time. He had driven less than three hundred meters when a quake more severe than any of the others struck. Suddenly behind him the break reversed itself, so that westward he would now have to climb a cliff of equal height returning eastward. The ground heaved and buckled like a tempestuous sea. violent that at one time the vehicle was hurled several meters sideways, and almost overturned. And the wind smashed down on it unrelentingly. send the groundcar speeding forward. The terrain was easier here, nearing the western edge of Den Hoorn, and he covered several kilometers before the wind struck again, cutting his speed down considerably. He judged he must be nearing Rathole. Not long thereafter, he rounded "—"Our Town." But he made no protest. to find a way. "No, it wouldn't work," he there were avenues between lines of heavy chains strung to short the way to Oostpoort would be so heavy the machine couldn't lift big enough to power it all them off the ground. If there away before one of them grabbed him and he was able to grasp the chain himself. They told him that. Whether Diego and outside. As soon as they reached ground level, the wind hit them. They dropped the platform He had been reading too much ancient history during his leisure hours. The hot monotony of Venus was beginning to affect his brain. It had been 500 years The wind caught the third and somersaulted him half a dozen times before he skidded to a stop A look at the men around him, the sound of their chatter, convinced him that he need not try There was flat ground to the east, clear in a fairly broad alley for at least half a kilometer before any of the domes protruded heavy chain that ran by the dome. The platform quivered and shuddered in the heavy wind, but its base was too low for it to overturn. Shortly the two men returned chain. Jan followed, and the other men fell in behind in single file. A hundred meters farther on, they turned, descended its exhaust, but they did not catch. "What is the matter, delayed." The woman seemed to sense his meaning. She turned and went back into the dome. "I should have known that," he said unhappily. "I would have "There's nothing that can be done," he repeated. "We can't make the trip overland because of the chasm out there in Den Hoorn, and we can't fly the platform Jan and Diego made their way little more than two hours before the G-boat's blastoff time, and it couldn't wait for them. It was and headed back eastward. It was easier driving with the wind behind him, and Jan hit a hundred kilometers an hour several times before striking the rougher ground of Den Hoorn. had earlier. It quivered constantly, like the surface of quicksand. The ground far ahead of him knew it was a life-or-death matter watching for the cliff he had to skirt and scale, had picked up speed over some fairly even terrain, but now he slowed again, puzzled. There was something wrong ahead. He couldn't quite figure it out. for him to be aboard the Vanderdecken when it blasted off for Earth, Jan did not know. years old and he was bright, and he must realize the seriousness involved in a decision to send him Diego, beside him, had sat all the way to Earth. Jan felt ashamed of the exuberant smaller. They skidded to a stop. The chasm that had caused him such a long detour before had widened, evidently in the big quake that had hit earlier. Now it was a canyon, half a kilometer wide. Five meters from the edge he looked out over blank space at the far wall, and could not see the bottom. Cursing choice Dutch profanity, northward and drove along the edge of the abyss as fast as he could. He wasted half an hour before realizing that it was getting no narrower. There was no point in going back southward. It might be a hundred kilometers long or a

<question>:
Why could the helicopters from the main settlement pick up Jan and Diego?

<options>:
A They were out of fuel
B The wind was too severe
C They had been moved north with the naval base
D The distance was too far

<answer>:

B