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

<passage>:
Two families fought for the title to Eros, and only one could win. One had to outsmart the other—and both had to win over the unscrupulous United Ores Corporation. It was a problem worthy of a Solomon—and it his chest caved in like he was carrying a heavy weight on his shoulders. That was from studying things through a microscope. Anyhow, decided Bobby with a fierce loyalty, that S.S.P. man probably wouldn't even Eleanor stood quietly beside Mom, crooning softly to The Pooch so it wouldn't be scared by the thunderous blast of rocket motors. Grampaw Cuchulainn do anything, everything at once. He took The Pooch into the circle of his left arm, helped his mother aboard, said, "Shut up, kid, you're waited, though, to see the cradle-monkey, the man under whose orders spacecraft lifted gravs. The cradle-monkey was a dour man with gnarled Cuchulainn understanding response fell again. "Now!" Bobby jabbed the button in frantic haste. Suddenly the silence was shattered by a thunderous detonation. There was a massive hand pressing him back into the soft, yielding leather of his chair the chair retreated on oiled channels, pneumatic compensators hissing faintly, absorbing the shock. Across the room a faulty hammock-hinge squeaked rustily. Then it was over as quickly as it had begun, and he could breathe again, and Dick was lurching across the turret on feet that wobbled queerly because up was down and top was bottom and everything was funny and mixed up. ball-like in the vastness of space. Earth, dwindling with each passing moment. Bobby moved to his side and watched Moira, too, and Eleanor Cuchulainn . Oh, it was enjoyable to stare through the observation panes at the flame-dotted pall of space—until Pop tried to turn his Cuchulainn Earth." "Don't I know it? It's almost a hundred million at perihelion. But that's not the lucky part. You sure had to pull strings to get the Frankly, I don't get it! Eros must have terrific mass to have the attributes of a full-sized planet." "It does, Richard. A neutronium core." It was not Dick's fault. It was just a tough break that no one had expected, planned for, guarded against. The planetoid was there beneath them they would land on it. It was as simple at that. Only it wasn't. Nor did they have any warning that the problem was more complex until it was too late to change their plans, too late to halt he had served two tricks on the Earth-Venus-Mars run. But all those planets were large Eros was just a mote. A spinning top.... "The night-line. We forgot to consider the diurnal revolution." "And now we've got to land in the dark. On strange terrain. Arragh! I should have my head examined. I've got a plugged tube somewhere!" "'What can't be cured,'" said Pop mildly, "'must be endured.' We have the forward search-beams, son. They will help." That was sheer optimism. As they neared the planet its gravitational attraction seized them tighter and tighter until they were completely under its compulsion. Dusk swept down upon them, the sunlight dulled, faded, grayed. Then as the ship nosed downward, suddenly all was black. Dick snapped, "Into your hammocks, everyone! Don't worry. This crate will stand a lot of bust-up. It's tough. A little bit of luck—" But there was perspiration on his forehead, and his fingers played over the control banks like frightened moths. There was no further need for the artificial gravs. Eros exerted, strangely, incredibly, an attractive power almost as potent as Earth's. Dick cut off the gravs, then the hypos. As the last machine-created Cuchulainn with angry fingers. Through howling Bedlam they tumbled dizzily and for moments that were ages long. While Dick labored frantically at the controls, while Moira watched with bated breath. Mom said nothing, but her hand sought Pop's Eleanor cradled The Pooch closer to her. Grampaw scowled. And then, suddenly— "Hold tight! We're grounding!" cried Dick. And instinctively Bobby braced himself for a shock. But there was only a shuddering jar, a lessening of the roar that beat upon their eardrums, a dull, flat thud. A sodden, heavy grinding and the groan of metal forward. Then a false nausea momentarily assailed him. Because Cuchulainn I'm afraid we've—er—selected a wet landing field. We seem to be under and gurgled. Water! Dick cried, "Hey, this is bad! We'd better get out of here—" He leaped to his controls. Once more the plaintive hum of the hypatomics droned through the cabin, gears ground and clashed as the motors caught, something forward exploded dully, distantly. The ship And on the fourth essay, there ran through the ship a violent shudder, broken metal grated shrilly from forward, and the water began bubbling "We can't get loose. The entire nose must be stove in! We're leaking like a sieve. Look, everybody—get into your bulgers. We'll get out through the airlock!" Mom cried, "But—but our supplies, Dick! What are we going to do for food, clothing, furniture—?" remember how to climb into 'em? Eleanor—you take that oversized one. That's right. There's room for you and The Pooch—" The water was almost ankle deep in the control room by the time they had all donned spacesuits. Bloated figures in fabricoid bulgers, they followed Dick to the airlock. It was weird, and a little bit Cuchulainn , they fled. The airlock was small. There was room for but one at a time. The water was waist—no, breast-deep—by the time all were gone save Bobby and Dick. Bobby, whose imagination had already assigned him the command of the foundering ship, wanted to uphold the ancient traditions by being feeling in his stomach. Almost immediately a hard something clanged! against his impervite helmet Dick's voice was metallic through the audios of the space-helmet. "All here, Pop? Everybody all right? Swell! Let's strike out for the shore, At that time, a few of the more imaginative astronomers offered the suggestion that this variation might be caused by diurnal rotation. After 1931, though, the planetoid fled from Earth. It was not until 1975, the period of its next approach, that the Ronaldson-Chenwith expedition visited it and determined the old presumption to be correct." "It looks worse every time I go back. I may not be able to get in the airlock again if the ship keeps on settling. The whole prow split wide open when we hit, the ship is full of water. The flour and sugar and things like that are ruined. I managed to get a few more things out, hypatomic out. I'd better, anyhow. If we're ever going to raise the ship, we'll need power. And atomic power is the only kind we can get in this wilderness." And he shook his head. "But we can't do it in a day or a week. It will take time." over-supplied." He thought for a minute. "If that's the way it is, we might as well move." "Move?" demanded Grampaw. "What's the matter with the place we're at?" "For one thing, it's too exposed. An open beach is no place for a Cuchulainn

<question>:
What was the root of the Cuchulainn's landing issue?

<options>:
A Rob's calculated coordinates were incorrect.
B Dick had failed to fix essential broken parts on the ship.
C Dick and Rob had anticipated landing during daylight hours, not at night.
D The gravitational pull was too strong.

<answer>:

C