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

<passage>:
Spawning Ground By LESTER DEL REY They weren't human. They were something more—and something less—they were, in short, humanity's hopes for survival! [Transcriber's Note: This etext was produced from hand across the dark stubble on his chin. It could wait. "Anything new 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 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 as cadets on their twelfth birthday. The two he'd drawn, Kaufman and Pinelli, seemed to be totally devoid of any sense of caution. Of course there was no obvious need for caution here. The blobs hadn't seemed dangerous, and the local animals were apparently all herbivorous and harmless. They were ugly enough, looking like insects in spite of their internal skeletons, with anywhere from four to twelve legs each on their segmented bodies. None acted like dangerous beasts. But back, and to the more recent ship under Hennessy that was sent to check it wasn't raining, though the ground was covered by thick swirls of fog. In the distance, the tops of shrubs that made a scrub forest glowed yellow-green. Motions around them suggested a herd of feeding animals. Details were impossible to see through the haze. Even the deep gorge where they'd found Hennessy's carefully buried ship was completely hidden by the fog. There were three of the blobs dancing about over the grazing animals now, as they often seemed to do. Gwayne stared at them for a minute, 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 his eye. 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. spite of the load of the two struggling boys! The creatures dived downward into lower ground, beginning to disappear into the mists. "Follow the blobs," Gwayne yelled. He realized now he'd been a fool to leave his suit the radio would have let him keep in contact with the kids. But it was too late to go back. The blobs danced after the horde. Barker bounced the jeep downward into a gorge. Somewhere the man had learned to drive superlatively but he the horde would all vanish in the uneven ground, hidden by the fog. A blob dropped down, almost touching Gwayne. He threw up an instinctive hand. There was a tingling as the creature seemed to pass around it. It lifted a few inches and drifted off. language or draw pictures. I want to know what happened to Hennessy and why that ship was buried against detection. This thing may be the metabolism." He sucked in on the cigarette he'd dug out, then spat 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." time and be better off than trying to dig through Hennessy's ship. That primitives have gotten to the men inside Hennessy's ship? Why was its fuel dumped? Only men would have known how to do that. And who told these creatures that a space ship's metal finders could be fooled by a little more than a hundred feet of solid rock? They'd buried the ship 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 finally proved that the sun was going to go nova. 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 the terraforming teams did what they could. And then the big starships began filling worlds with colonists, carried in deep sleep to conserve space. 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 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 Gwayne dropped the phone and headed for the little sick bay. He swore gets easier as you listen. It's Hennessy, all right. I'm certain." germ plasm. But in this case, what changed Hennessy is real, so maybe Gwayne led the former Hennessy to the exit. The waiting blobs dropped set the combinations and pressed the studs. There was a hiss and gurgle 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. however much they might hate it at first. But there was no putting off giving the gist of it to Jane. "It was the blobs," he summarized it. "They seem to be amused by men. They don't require anything from us, but they like us around. Hennessy doesn't know why. They can change our cells, adapt us. Before men came, 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 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 eyes. And in time, Earth wouldn't even be a memory to this world. puzzlement in her face. "Why?" And then, before he could answer, her own intelligence gave her the 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 fruitful," she whispered. "Be fruitful and spawn and replenish an 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 children of men!

<question>:
Why was the fuel drained out of Hennessy's ship's tank?

<options>:
A Gwayne doesn't know
B Hennessy drained it so they couldn't leave
C it was destroyed by creatures from the planet
D the blobs used it for energy

<answer>:

B