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

<passage>:
By ROBERT ABERNATHY Gigantic, mindless, the Monsters had come out of interstellar space to devour Earth. They gnawed at her soil, drank deep of her seas. Where, on the U.S. copyright on this publication was renewed.] Westover got a shock when he stumbled onto the monster, for all that he the slime that covered a surface faintly, horrifyingly resilient. He recoiled as if seared, and retreated, slithering in the muck. For moments his mind was full of dark formless panic quiescent until morning—sleeping, if such things slept. And that explained the flood the monster's body had formed an Westover stood motionless in the blackness 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 which he had to make before dawn ... but not now ... not now.... He lay in a state between waking and dreaming, high on the monster's side below, and beneath the black cloud something that writhed and flowed sluggishly in a cyclopean death agony. the dry land. "The monsters who have descended on Earth must represent the end result 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 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 sheer bulk and mindless hunger. Near the crest of the monster's back, he stumbled and fell hands and knees on the shagreen-roughness of the skin at first he thought only that an attack of dizziness had made him fall, then he realized that to glimpse Sutton's face, as the biologist calmly made that grisly report to the President's Committee on Extermination.... Sutton's prediction had been a hundred percent correct. The monsters' hunger knew no halt until they had absorbed into themselves all the organic material on the world which was their prey.... And men must starve, as he was starving now.... With a struggle Westover roused himself, first sitting up, then swaying hack with feverish industry at the monster's crusted hide. The scaly, weathered epidermis seemed immeasurably thick. But at last he had chopped through it, reached the softer protoplasm beneath. Clawing and hewing in the hole he had made, he tore out heavy slabs of the monster's flesh. A ripple that did not belong to the crawling motion ran over the thing's surface round about. Westover laughed wildly with a sudden The analogy was pat like a flea, he had lodged on a larger animal and was about to nourish himself from it. The slabs of flesh he had cut off were gray and unappetizing, but he knew from the studies he had helped Sutton make that the monsters, extraterrestrial though they were, were in the basic chemistry of proteins, fats and carbohydrates one with man or the amoeba, and therefore might be—food. His matches were dry in their water-proof case he made a smoldering fire from the loose fibrous scale of the monster's back, and half an hour later was replete. Either the long fast, or involuntary revulsion, or perhaps merely the motion of the creature brought on nausea, but he fought it sternly back and succeeded in keeping his strange meal down. Then he was tormented by thirst. It was some time, though, before he could bring himself to drink the colorless fluid that had collected in the wound he had inflicted on the monster. Thus began for him a weird existence—the life of a parasite, of a flea on a dog. The monster crawled by day and rested by night strengthened, only source of food he knew in all the world—not just that he was developing a flea's psychology. He was a man and a scientist, and he was conducting an experiment.... His life on the monster's back was proving something, something of vast importance for man, the extinct animal—but for increasingly longer periods of time he could not Westover's mind was beginning to function again 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 the fresh breeze and sniffing the air he recognized the salt tang of the sea. While he slept the monster had crept beyond the coast line, and lay now in what to it was shallow water—fifty or a hundred beasts fought crazily over the last morsels of food. He had lost track of the days he had been on the monster's back, but the rape of Earth must be finished now. He had no doubt that the things would depart Westover sat for a space with head in hands, hearing the faint He paused to listen with fierce intentness, and heard nothing but the faint eructations deep inside the monster. Then he sprang to his feet, gripping his hand-ax, and ran panting to the place where he had dug for food. His excavations tended to close "Who are you?" asked Westover, breathlessly but almost without surprise. Westover hesitated. "I'm not just imagining you?" he appealed. Westover was still not sure that the other was more than one of the the sheer horror of the yielding beslimed walls that seemed every moment squeezing in to trap them unspeakably. The air was warm and rank with the familiar heavy sweetish odor of the monster's colorless blood.... and Westover climbed to his feet and stood, weak-kneed still, staring told Westover better than words that there was something hugely he and Westover froze in dumbfounded recognition. Westover finished the brief account of his coming to dwell on the "I haven't got so far with the theory," said Westover, "but I think I've got the main outlines. Until the monsters came, man was a parasite on the face of the Earth. Fundamentally, parasitism—on the green plants and their by-products—was our way of life, as of all animals from the beginning. But the monsters absorbed into themselves all the plant food and even the organic material in the soil. So we have only monster is so much like us in fundamental makeup that its body contains all the elements human life needs too." "Then," Westover glanced appreciatively around, "it looks like the main Westover flexed his hands involuntarily, like one who has been too from an endoparasite's point of vantage, merely by isolating from the creature's blood over a long period enough of some potent secretion—hormone, enzyme or the like—to kill when suddenly Westover stared. "Why?" "No! Of course I realize—Well, I see what you mean—I think." Westover we'll do better to model ourselves on the humble tapeworm. "Your idea is dangerous for the same reason. The monsters probably Westover bowed his head, but he had caught a curiously expectant glint Earth, because it's on such worlds they prey. A tapeworm can cross the Sahara desert in the intestine of a camel—" His voice was drowned in a vast hissing roar. An irresistible pressure

<question>:
What was not a reason that Westover felt sick to his stomach?

<options>:
A He had been fasting a long time
B He felt revulsion at eating the monster
C He had motion sickness from riding the monster
D The monster's flesh had a bad taste

<answer>:

D