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

<passage>:
this gutted cosmic carcass, could humanity flee? Westover got a shock when he stumbled onto the monster, for all that he knew one had been through here. He had been following the high ground toward the hills, alternately ponderous repose across the river valley, its head and tail spilling if it did not move until dawn, the level would be far higher then. Westover stood motionless in the blackness how long, he did not know. He was hardly aware of the water that covered his feet, crept over his ahead was blocked by the titanic enemy. Then the impersonal will that had driven him implacably two days and nights without stopping came to his rescue. Westover plodded forward, pressed his shrinking body against the slimy, faintly warm surface of the monster's foot, and sought above him with upstretched hands—found to be climbed. Westover felt poignantly that his exhausted body could not make that ascent and face the long and dangerous descent beyond, which he had to make before dawn ... but not now ... not now.... side Westover had been one of the men who, in the days when humanity was still fighting, had accumulated quite a store of knowledge about the enemy—the enemy that was brainless and toolless, but that was simply too vast for human intelligence and weapons to defeat.... Westover no longer saw the murky moonlight, the far faint glitter of the flood or the slope of the living mountain. He saw, as he had seen from a circling jet plane, an immense tree of smoke that rose and favored unicellular growth. Probably as a result of this unspecialized the same reason they have achieved what even intelligent cellular life so far hasn't—liberation from existence bound to one world's surface, the dry land. "The monsters who have descended on Earth must represent the end result monsters have finished with Earth, there will be no vegetation left for man's food, no houses, no cities, none of the fixed installations of civilization, and the end will be far more terrible than if we were all devoured by the monsters." Westover awoke, feeling himself bathed by the cold sweat of nightmare—then he realized that a misty rain had wetted his face and sogged his clothes. That, and the sleep he had had, refreshed him and struggling through the clouds and mist, becoming every moment less tenuous and illusory, more the bitter reality of the breaking day. Even as Westover began frantically climbing, out of that lightening sky the hopelessness of his effort pressed down on him. With dawn the monster would begin to move, to crawl eastward impelled by the same dim phototropic urge which must guide these things out of the interstellar around the Earth, gutting the continents and churning the sea bottoms, still lived and wandered over the once populous fertile lands, like this—would not live long. For a man like Westover, who had been a scientist, it was not the prospect of death that was most crushing, but the death blow to his human pride, the star-storming pride of mind and will—defeated by With a struggle Westover roused himself, first sitting up, then swaying to his feet, frowning with the effort to look sanely at the terrible A ripple that did not belong to the crawling motion ran over the thing's surface round about. Westover laughed wildly with a sudden sense of power. He, the insignificant human mite, had made the Presently, though, he felt a faint shuddering and lift beneath his feet, and heard far stifled mutterings and sighs. Westover's mind was beginning to function again it was as though the cessation of the rock and sway had exorcised the lethargy that had lain that had been killed by atomic bombs, the answer to the riddle of odd degenerate relatives of the vertebrates that are called tunicates because of their gaudy cellulose-plastic armor.... The monster on which Westover had been living as a parasite was generating gases within itself, preparing to leave the ravished Earth. That was the meaning of its gargantuan belly rumblings. And they meant that blue headland could be only a land made desert, where men become Westover sat for a space with head in hands, hearing the faint continuing murmurs from below. And he remembered the voices. He had been hearing them again as he awoke—the distant muffled voices Westover hesitated. "I'm not just imagining you?" he appealed. "Somebody else has really found the answer?" The Preacher's brows knitted faintly, but then his look turned to benevolent understanding. "You have been alone too long here. Come with me—I will take you to the Doctor." Westover was still not sure that the other was more than one of the powerful specters of childhood—the Preacher, the Doctor, no doubt the Teacher next—risen to rob him of his last shreds of sanity. But he at a black rent in the rugose hide, the mouth of a burrow descending into utter blackness—Westover knew that both the Preacher and his own wild hope were real. and Westover nodded this time with alacrity. The crawling descent through the twisting, Stygian burrow had much the trays, rising and bursting, rising and bursting with a curiously fascinating monotony. The subtly tense attitudes of the two initiates told Westover better than words that there was something hugely important in the success of whatever magic was producing those bubbles. turned with a satisfied grin on his round, spectacled face—then both he and Westover froze in dumbfounded recognition. quick eyes studied Westover's face, and he gestured toward a packing Sutton nodded thoughtfully. "It was too late—or too early, perhaps. We'll have to talk that over." Westover finished the brief account of his coming to dwell on the monster's back. The other grinned happily. "You began with the practice, where I worked out the theory first." "I haven't got so far with the theory," said Westover, "but I think "Then," Westover glanced appreciatively around, "it looks like the main hazard is claustrophobia." a temporary expedient. Human history hasn't had such a turning-point for the rest of our lives—and our children's and our children's biologists' reunion, "the Lord will provide, even as He did unto Jonah when he cried to Him out of the belly of the fish." "Amen," agreed Sutton. But the gaze he fixed on Westover was oddly troubled. "Speaking of the future brings up the question of the idea Westover flexed his hands involuntarily, like one who has been too long enforcedly idle. In terse eager sentences he outlined for Sutton the plan that had burned in him during his bitter wandering over "Beautifully simple." Sutton smiled wryly. "So much so that I wish you'd never thought of it." Westover stared. "Why?" "Describing your plan, you sounded almost ready to put it into effect on the spot." "No! Of course I realize—Well, I see what you mean—I think." Westover was crestfallen. Sutton smiled faintly. worlds our descendants will inhabit. It's too much dynamite to have around the house." Westover bowed his head, but he had caught a curiously expectant glint in Sutton's eyes as he spoke. He thought, and his face lightened. "Suppose we work out a way to record my idea, one that can't be riddle for our descendants—who should have use for it some day." At last Sutton smiled. "That's better. You've thought it through to the end, I see.... This phase of our history won't last forever. Eventually, the monsters will come to another planet not too unlike Earth, because it's on such worlds they prey. A tapeworm can cross the knowing his words lost in the thunder, gestured toward the Earth they were leaving, a half-regretful, half-triumphant farewell.

<question>:
Do you think this story has a happy ending given Westover's goals?

<options>:
A It's a happy ending
B Not at all
C It's bittersweet
D It's not a happy ending for Westover but it is a happy ending for the other characters

<answer>:

C