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

<passage>:
Agents had killed her husband. That was back in '07, on the eve of his departure for Alpha Centaurus but she never spoke of this Once, in the second year after her husband's death, an Agent came and stayed in one of her cabins. She learned that he was an Agent completely by accident. While cleaning the cabin one morning his badge fell out of a shirt pocket. She stood still, staring at the horror of it there on the floor, the shirt in That night she soundlessly lifted the screen from the window over his bed and shot him with a .22 rifle. She threw the weapon into the river. It helped very little. He was one Agent, only one out of all the thousands of Agents all over Earth while her husband had been one of twenty-eight persons. She decided then that her efforts would be too ineffective. The odds were wrong. Together they would seek revenge. He did not have the cylinder—not violently, so that she was forced to slap him to prevent hysteria. She side." He turned back, a dawning comprehension showing in his eyes. "That's right, you're one, too. That is why you killed that Agent in the third cabin." It was her turn to be surprised. "You knew about that?" "I saw you. I wasn't sleeping. I was afraid to stay inside alone, so I followed you. I never told anyone." It was a subject of wonder and much speculation, but no one took serious notice of them until one night a federal Agent arrested one man chosen spot, it arrived without clothes. The arrested man disappeared from his jail cell, and the next morning the Agent was found strangled to death in his bed. This set off a campaign against Konvs. One base act led to another, until the original reason for noticing them at all was lost. Normal men no longer thought of them as human. He returned for the others. They gathered one night in a dirty, broken-down farmhouse in Missouri—and disappeared in a body, leaving the Agents standing helplessly on Earth, shaking their fists at the sky. the group left. They shot him in the back, and the others had to go on without him. Now do you know why I killed the Agent in the third cabin? For the remainder of that summer they worked together. They practiced at night mostly, taking longer and longer jumps, until Earl's confidence allowed him to reach any part of the Earth he chose. She knew the habits of Agents. She knew how to avoid them. They would select a spot sufficiently remote to insure detection, she would devise some prank to irritate the Agents then they would quickly for some clue to their identity. It was inevitable that they should identify Mrs. Jamieson as one of the offenders, since they had discovered, even before Stinson took his describe the horror in Lisa's young mind when the news went out that E. Mason Jamieson had been killed. She wanted him to learn as much as possible about his father's death, knowing that soon the Agents would be after Earl. They were so clever, so persistent. She wanted him to be ready, not only in ways of avoiding their traps ... but ready with a Agents" now with a curl of his lip. They had been successful in contacting other Konvs, and sometimes visited them at a remote rendezvous. he would have fully avenged his father's death. He was clever and intelligent. He could kill many Agents. So she exhumed the money she had hidden more than ten years before. It was also convenient for coming home late at night after Agent hunting. Mrs. Jamieson was becoming obvious. Excitement brought color to her cheeks when she thought of Earl facing she soon grew aware of her mistake. One day he disappeared. Mrs. Jamieson was alarmed. Had the Agents found him? She watched the The second day after his disappearance she found a small item. A Konv had raided the Agent's office in Stockholm, killing three, and getting killed himself. Mrs. Jamieson dropped the paper immediately and went to Stockholm. She did not consider the risk. In Stockholm she found clothes and made discreet inquiries. The slain man had been a Finnish Konv, one of those left behind by Stinson as an undesirable. His wife had been killed by the Agents the week before. He had gone completely insane and made the raid singlehanded. Mrs. Jamieson read the account of crimes committed by the man and his wife, and determined to prevent "What did you do?" she asked. Suddenly he flung the pencil down, jumped from his chair and paced the floor. "I talked to an Agent last night," he said. "Where?" Mrs. Jamieson had to sit down. Finally she was able to ask, "How did it happen?" "I broke into the office there to get at the records. He caught me." "What were you looking for?" "I wanted to learn the names of the men who killed Father." He said the "I don't know," he said. "Curiosity, maybe, or a subconscious desire for revenge. I just wanted to see them." "Tell me what happened! If an Agent saw you ... well, either he killed you or you killed him. But you're here alive." "I didn't kill him. That's what seems so strange. And he didn't try to kill me. We didn't even fight. He didn't ask why I broke in without Mrs. Jamieson stopped on her way out of the room and laid a hand on his arm. "Your father would have been proud of you," she said. "Soon you will learn the truth about the Agents." Beyond the closed door, out of sight of her son, Mrs. Jamieson gave rein to the excitement that ran through her. He had wanted the names! her. She didn't know where the men were now, those who had killed her husband. They could be anywhere. Agents moved from post to post And they were in the best position to gain them. She was consumed by fear that one or more of the men on Earl's list might have acquired a cylinder and were now Konvs themselves. Two weeks later she read a news item saying that Tom Palieu had been killed by a Konv. The assassin's identity was unknown, but agents were working on the case. She knew. She had found a gun in Earl's desk. She took the paper into Earl's room. "Did you do this?" He turned away from her. "It doesn't matter whether I did or not. They will suspect me. His name was on the list." "They will," she agreed. "It doesn't matter who the Konv is, now that an Agent has been killed. The one in Bangkok will tell them about you and the list of names, and it's all they need." "Well, what else can he do?" Earl asked. "After all, he is an Agent. If one of them is killed, he will have to tell what he knows." "You're defending him? Why?" she cried. "Tell me why!" He removed her hand from his arm. Her nails were digging into his flesh. "I don't know why. Mother, I'm sorry, but Agents are just people to me. I can't hate them the way you do." calmly. "They won't find us." "Oh, yes they will," she said. "Don't underestimate them. Agents are picked from the most intelligent people on Earth. It will be a small job for them. Don't forget they know who you are. Even if you hadn't been so stupid as to tell them, they'd know. They knew my pattern from the time your father was alive. They got yours when we were together He was entirely nude ... but it seemed natural and right. Then Mrs. Jamieson saw him. Earl said, "Why was my father killed?" "By mistake. Back in those days, like now, there were good Konvs and bad. One of those not selected by Stinson to join us was enraged, half crazy with envy. He killed two women there in Bangkok. The Agents her son were gone. Her outstretched hands touched nothing. Her power was gone! The Agents stepped into the room over the broken door. She stared at them, then ran to Earl's desk, fumbling for the gun. The Agents' guns rattled.

<question>:
Why did the woman kill the man in the third cabin?

<options>:
A She thought he was there to kill Earl
B She thought he was there to kill her
C He said he was an agent
D She found out he was an agent

<answer>:

D