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

<passage>:
MUCK MAN she had thought crimes were committed by shriveled, rat-faced types, and not by young biological engineers who still affected crewcuts. the courtroom and down the corridor back to jail. Jumpy, Asa's cellmate, took one look at his face as he was put back behind bars. with his head bent and turned to face Jumpy. to be a muck man, Jumpy. I'm going out to Jordan's Planet and hunt Planet, with his physiology adapted to the environment of that wretched world, he could study the eggs under conditions no laboratory could of altered shape before they signed a release. The requirement held senescence could be staved off, however, any man could have bulging biceps and a pencil waist, if he could pay for the treatment. Until the medical associations declared such treatments unethical there was even a short fad of deliberate deformities, with horns at the temples particularly popular. worlds man had discovered. Even on Mars, the only planet outside Earth in the solar system where the human anatomy was remotely suitable, a man could work more efficiently with redesigned lungs and temperature controls than he could inside a pressure suit. On more bizarre planets a few light-years away the advantages of changeling bodies were permitting a convicted criminal to earn his freedom by putting in one year as a changeling for every five years he would otherwise have had muck men on Jordan's Planet." "Why such a difference? Everyone knows about muck men living in the mud while they hunt Slider eggs. But don't your conversions make the changeling comfortable in his new environment?" "Sure they do," said the doctor. "We can make you think mud feels Since it was cheaper to transport a normal human than to rig special one of them sounded like a woman's. But since women neither served on cellmate, another convict who had elected conversion to muck man. More had wanted to return. "It's the Slider eggs," explained Kershaw, the two-time loser. "The ones you see on Earth knock your eyes out, but they've already begun to die. There's nothing like a fresh one. And I'm not the first to filaments that served as a yolk. Along these interior threads played Hardly anyone faced with the beauty of a Slider's egg bothered to question its workings. For a few expectant moments there would be only random, fitful gleamings, and then there would be a wild coruscation of light, dancing from one filament to the next in a frenzy of brilliance. It took about four years for a Slider egg to die. Beauty, rarity and fading value made the eggs a luxury item like nothing the world had ever seen. If Asa had found a means of keeping them alive it would have made him wealthy at the expense of the Hazeltyne monopoly. to lose consciousness. "This is it!" he thought in panic. eyes. Everyone had seen pictures of muck men. It was different having one stand beside you. Kershaw looked much like an enormous frog except that his head was still mostly human. He was sitting on webbed feet, his lower legs bent double under huge thighs, and his trunk tilted forward so that his arms dangled to the ground. The arms were as thick around as an ordinary man's legs. The hands had become efficient scoops, with This, Asa realized, was what he looked like himself. It would have been more bearable if the head had not retained strong traces of humanity. The nostrils flared wide and the jaws hardly emerged from the neck, but the ears were human ears and the eyes, under of Jordan's Planet and turned most of its surface into marsh and mud flats. A high wall enclosed the far portion of the courtyard. Ranged along the wall were thirty stalls for muck men. From fifty yards across the courtyard a muck man bounded over to them in two leaps. Attached to a harness across his shoulders and chest were "Names?" he growled. He was a foot taller than Graybar and big distorted body, to teach him how to leap and how to dig. He was shown how to operate the radio he would carry and how to fire the pencil-slim native vine. He did so and immediately vomited. Furston laughed. "That's to remind you you're still a man," Furston said, grinning. At supper that night, squatting on the ground beside a low table with the dozen other muck men operating from the dome, Asa asked what the carry any eggs the muck men found. He gave each man a compass and Graybar aside. "In case you don't like it here," Furston said, "you can get a week knocked off your sentence for every egg you bring in. Now get out there and work that muck." courtyard was to keep Sliders out, not muck men in. He leaped over it mud, if not precisely as pleasant to the touch as chinchilla fur, was not at all uncomfortable, and the dripping air caressed their skins like a summer breeze back on Earth. Tiny, slippery creatures skidded At each leap along the trail they peered quickly around. They saw no Sliders, but this meant little, for the beasts lived under the mud as much as on top of it. the muck. a muck man dug in a spiral out from the center, but Graybar and Kershaw dug in gradually widening semi-circles opposite each other. They had big enough to stand in. Each handful of mud had to be squeezed gently before it was thrown away, to make sure it didn't conceal an egg. As he worked, Asa kept thinking what an inefficient system it was. Everything slime off a round object the size of a baseball. Asa jumped out to earphones and he thought of what Kershaw had said, that the scintillation of an egg was an effect of its calls to a mother Slider scales, some two feet thick and six feet high, had reared up out of the weeds. The top segment was almost all mouth, already opened to show row "We've got an egg but a Slider wants it back." the Slider's first rush, for he was trying to hop on one leg as if the other had been broken. The egg lay flickering on top of the mud where flesh. The Slider writhed, coating its wound in mud, and twisted toward Asa. He leaped to one side, firing from the air and missing, and saw the Slider turn toward the patch of weeds where he would land. His legs were tensed to leap again the moment he hit the mud, but he saw the Slider would be on top of him before he could escape. As he landed he with shreds of alien flesh scattered by the rocket's explosion. Desperately pushing himself to his feet, he saw the long headless body shiver and lie still. "Thanks," Kershaw said. "Muck men stick together. You'll make a good "Last time I was here there was about one mucker killed for every six eggs brought out. Of course you're not supposed to stand there admiring the eggs like I did while a Slider comes up on you." where it rested on the mud. He scooped a hole in the muck and buried "Just in case there are any more Sliders around," he explained. settled down on broad skids. Through the transparent nose Asa could see Kershaw, as a muck man, would have weighed close to three hundred "You do what I tell you, mucker," said Dorr. egg any time with some other muck man to dig for it. which he and Kershaw had certainly deviated on their outward trip. "The Slider you killed would draw them like ants to jam." eyed the helicopter with distaste at the thought of what a flimsy fort while she stared at him patiently. "What happened to the other muck men

<question>:
What was the advantage of muck men being shaped like frogs?

<options>:
A A frog-shaped body warded off Sliders.
B A frog-shaped body helped better cross the terrain on Jordan's Planet.
C A frog-shaped body would ensure prisoners could not leave Jordan's Planet.
D The frog body would be so grotesque that it would make it nearly impossible for prisoners to finish their sentence.

<answer>:

B