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

<passage>:
Korvin's arrival a necessity. They were well into the atomic era, and Korvin stretched out on the cell's single bunk, a rigid affair which he still didn't show any particular psi talents. He couldn't unlock the cell door with his unaided mind to the wonder and amazement of his Tr'en captors. He could do, as a matter of fact, precisely nothing. He wished quietly that the Tr'en had seen fit to give him a pack of cards, or a book, or would at least have been other prisoners to talk to. But on Tr'en Korvin was all alone. discuss almost anything from philosophy to plumbing, but there was nobody to discuss it with. He changed position on the bunk and stared imperfections in the smooth surface to distract him. He wasn't tired and he wasn't hungry his captors had left him with a full stock of food concentrates. But he was almightily bored, and about ready to tell anything to Korvin didn't know why, and neither did anybody else. There were a lot of theories, but none that accounted for all the facts satisfactorily. Korvin It was a ritual, Korvin had learned. "You are of the Tr'en," he the door behind him. Korvin thought of jumping the Tr'en, but decided "What do you want with me?" Korvin said. The Tr'en speech—apparently "I want nothing with you," Didyak said, leaning against the door-frame. "You have other questions?" Korvin sighed. "What are you doing here, then?" he asked. As pointed. Korvin stared back impassively. "I have been ordered to come to you," Didyak said, "by the Ruler. The Ruler wishes to talk with you." and Didyak had used a specific meaning, roughly: "gain information from, by peaceful and vocal means." Korvin filed it away for future reference. "Why did the Ruler not come to me?" Korvin asked. "The Ruler is the Ruler," Didyak said, slightly discomfited. "You are to go to him. Such is his command." Korvin shrugged, sighed and smoothed back his hair. "I obey the command of the Ruler," he said—another ritual. Everybody obeyed the command of the Ruler. If you didn't, you never had a second chance to try. But Korvin meant exactly what he'd said. He was going to obey the commands of the Ruler of the Tr'en—and remove the Tr'en threat from Korvin wasn't attempting to escape. He wasn't pleading with the Ruler. He wasn't defying the Ruler, either. He was just answering questions. The Tr'en liked to have everything clear. They were a logical race. The Ruler had started with Korvin's race, his name, his sex—if said apologetically. "Slipshod," the Ruler muttered. "Undoubtedly," Korvin agreed politely. "I'll try to do the best I can for you." "You will answer my questions," the Ruler said, "with exactitude." He paused, frowning slightly. "You landed your ship on this planet," he went on. "Why?" The Tr'en, under other circumstances, would have been a valuable He hoped the lie-detector had been adjusted correctly. If it showed him telling an untruth, he wasn't likely to live long, and his job—not to mention the strongest personal inclinations—demanded most strongly that he stay alive. He swallowed hard. But when the technicians forced him down into the "I am not," he said. The Ruler looked to his technicians for a signal, and nodded on receiving it. "You will tell an untruth now," he said. "Are you standing or sitting?" to him. But, after all, the Tr'en knew their business, better than Korvin decided to throw his first spoke into the wheel. "Staying alive." The Ruler roared. "Do not waste time with the obvious!" he shouted. "Do not try to trick us we are a logical and scientific race! Answer correctly." "I have told the truth," Korvin said. "But it is not—not the truth we want," the Ruler said. Korvin shrugged. "I replied to your question," he said. "I did not know that there was more than one kind of truth. Surely the truth is the truth, just as the Ruler is the Ruler?" "I—" The Ruler stopped himself in mid-roar. "You try to confuse the Ruler," he said at last, in an approximation of his usual one. "But the Ruler will not be confused. We have experts in matters of right-saying —"who will advise the Ruler. They will be called." Korvin's guards were standing around doing nothing of importance now chulad-like Korvin translated—"attempts will get you nowhere." Korvin devoutly hoped so. The experts in logic arrived shortly, and in no uncertain terms Korvin indicators of the lie-detector with great care. "What is your plan?" he said at last, in a conspiratorial whisper. "To answer your questions, truthfully and logically," Korvin said. The silence this time was even longer. Korvin was very glad that wasn't a question. It was, after all, the "It has no name," Korvin said truthfully. The Tr'en idiom was like the The key question had, at last, been asked. Korvin felt grateful that of going off after details of armament first it saved a lot of time. "The answer to that question," Korvin said, "cannot be given to you." "Any question of fact has an answer," the Ruler snapped. "A paradox is not involved here a government exists, and some being is the "True," Korvin said again. The ruler sighed gently. "Explain this governor to us," he said. Korvin shrugged. "The explanation cannot be given to you." The Ruler turned to a group of his experts and a short muttered conversation took place. At its end the Ruler turned his gaze back to "Then you will suffer unpleasant consequences if you describe it to us?" the Ruler went on. Korvin noticed that the Tr'en were becoming slightly puzzled they were no longer moving and speaking with calm assurance. The plan was taking hold. The Ruler had finished his conference. "You are attempting again to confuse us," he said. Korvin shook his head earnestly. "I am attempting," he said, "not to confuse you." "Then I ask for an answer," the Ruler said. "I request that I be allowed to ask a question," Korvin said. The Ruler hesitated, then nodded. "Ask it," he said. "We shall answer it if we see fit to do so." from a knot of Tr'en, inclined his head in Korvin's direction, and began. "Our government is the only logical form of government," he said in a high, sweet tenor. "The Ruler orders all, and his subjects obey. In this way uniformity is gained, and this uniformity aids in expression. They needed no words the lie-detector was telling them, perfectly obviously, that he was speaking the truth. But the truth wasn't making any sense. "I told you you wouldn't understand it," he said. "It is a defect in your explanation," the Ruler almost snarled. "My explanation is as exact as it can be," he said. The Ruler breathed gustily. "Let us try something else," he said. for, no one being can have the force to compel acceptance of his commands. Without his force, there can be no effective rule." One of the technicians chimed in: "The machine tells us—" "Then the machine is faulty," the expert said. "It will be corrected." Korvin wondered, as the technicians argued, how long they'd take Korvin found himself the object of more attention than he had hoped for one by one, the experts came to his cell, each with a different method of resolving the obvious contradictions in his statements. Some of them went away fuming. Others simply went away, puzzled. On the third day Korvin escaped. Korvin thanked his lucky stars that their genius had been restricted the Tr'en aren't about to come

<question>:
Why did the Tr'en let Korvin go?

<options>:
A He represented an unsolveable problem
B He would not tell the truth
C He disrespected the ruler
D He refused to answer questions

<answer>:

A