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

<passage>:
criminal. There was, perhaps, a crease of puzzlement in her brow, as if she had thought crimes were committed by shriveled, rat-faced types, and not by young biological engineers who still affected crewcuts. behind bars. "Guilty," Jumpy said. Asa glared at him. "I know, I know," Jumpy said hastily. "You were framed. But what's the rap?" "Five or one." air-conditioned rehab clinic. A year on a changeling deal will seem a with his head bent and turned to face Jumpy. "Nope," Asa said softly. "I'm going into a conversion tank. I'm going to be a muck man, Jumpy. I'm going out to Jordan's Planet and hunt of so-called social reorientation. But if he could get out to Jordan's Planet, with his physiology adapted to the environment of that wretched world, he could study the eggs under conditions no laboratory could for all persons who elected changeling status. The law stated that potential changelings must be fully informed of the rights and hazards of altered shape before they signed a release. The requirement held By the time humanity traveled to the stars, medical biology had made 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 techniques were perfected to adapt humans to the dozen barely habitable worlds man had discovered. Even on Mars, the only planet outside Earth in the solar system where the human anatomy was remotely suitable, a controls than he could inside a pressure suit. On more bizarre planets a few light-years away the advantages of changeling bodies were wanted to become a changeling. High pay lured few. So a law was passed year as a changeling for every five years he would otherwise have had "What types of changelings do you have orders for right now, doctor?" asked for Jordan's Planet without some preliminary questions. with the arm structure modified into pseudo-wings or gliding. Then we need spiderinos for Von Neumann Two. If you want the nearest thing we have to Earth, there's Caesar's Moon, where we'd just have to double your tolerance for carbon monoxide and make you a bigger and better gorilla than the natives. Last, of course, there's always a need for muck men on Jordan's Planet." The doctor shrugged, as if naturally no one could be expected to choose Jordan's Planet. Asa frowned in apparent consideration of the Asa raised his eyebrows. "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?" better than chinchilla fur and we can have you jumping like a grasshopper despite the double gravity. But we can't make you like the sight of yourself. And we can't guarantee that a Slider won't kill you." He leaned forward to fill in the necessary form. Since it was cheaper to transport a normal human than to rig special environments in a spaceship, every planet operated its own conversion chambers. On the space freighter that carried him from Earth Asa Graybar was confined to a small cabin that was opened only for a guard to bring meals and take out dirty dishes. He was still a prisoner. spaceships nor worked in the dome settlements on harsher worlds, he Nevertheless his time was not wasted. He had as a companion, or cellmate, another convict who had elected conversion to muck man. More important, his companion had done time on Jordan's Planet before and 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 the albumen was just as clear around the sparkling network of organic Electrical instruments picked up static discharges from the egg, but the egg calling its momma. They sparkle like a million diamonds when Asa Graybar kept his normal form on Jordan's Planet just long enough to learn the discomfort of double gravity. He was told he needed another to back out of becoming a changeling, that he was on his way to the 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 claws. The skin was still pinkish but had become scaly. Not a thread of hair showed anywhere on the body, not even on the head. 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 where they had been left to revive from conversion. of Jordan's Planet and turned most of its surface into marsh and mud 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 a gun and a long knife. "Names?" he growled. He was a foot taller than Graybar and big everywhere in proportion. distorted body, to teach him how to leap and how to dig. He was shown "Everything that grows on this planet is poison. So if you got any lifted his head to breathe deeply and saw two humans watching him from The girl's presence merely puzzled Asa, but Dorr's being here worried At supper that night, squatting on the ground beside a low table with "The girl will inherit this racket some day, won't she?" asked one of not at all uncomfortable, and the dripping air caressed their skins like a summer breeze back on Earth. Tiny, slippery creatures skidded Sliders, but this meant little, for the beasts lived under the mud as Kershaw halted again when they came to a roughly circular area some ten the muck. "We're in luck," he said as Asa skidded to a stop at his side. "An egg dug in gradually widening semi-circles opposite each other. They had before it was thrown away, to make sure it didn't conceal an egg. As he scintillation of an egg was an effect of its calls to a mother Slider "Jump!" he shouted. At the edge of the clearing a segmented length of greenish black scales, some two feet thick and six feet high, had reared up out of the other had been broken. The egg lay flickering on top of the mud where with shreds of alien flesh scattered by the rocket's explosion. "Makes no difference," said Kershaw, pointing upward. "Here comes the settled down on broad skids. Through the transparent nose Asa could see helicopter, Asa got under his companion's belly and lifted him by the waist. He hadn't realized before just how strong his new body was. Kershaw, as a muck man, would have weighed close to three hundred pounds on Earth, close to six hundred here. Dorr stared at him with narrowed eyes. Suddenly he smiled in a way that for the egg. Finally he realized that Dorr could locate the egg which he and Kershaw had certainly deviated on their outward trip. What was the night like on Jordan's Planet? Maybe Sliders slept at this strange new body, and if the Sliders left him alone.... carcass of the dead Slider and took shelter behind it. She looked up at the machine-gun on the helicopter. "They feed at night, you know. And they eat their own kind," she said. "The Slider you killed would draw them like ants to jam." eyed the helicopter with distaste at the thought of what a flimsy fort to Jordan's Planet on a fancy tour. I told him the real reason I was "Oh, back on Earth I can make a helicopter do stunts. But I wasn't used

<question>:
The changelings on Jordan's Planet most closely resembled what Earth-dwelling creature?

<options>:
A A frog.
B A salamander.
C A worm.
D A gorilla.

<answer>:

A