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

<passage>:
SILENCE IS—DEADLY Curtis recalled that Nelson and Androka had long conversations radio—silence of that sort would be deadly! concentration, as his bushy gray head bent over his drawing board. Androka had arrived on board the which were now stored in the forward hold. Androka had watched over his treasures with the jealous care of a mother hen, and spent hours daily in the room in the superstructure that had been assigned as his laboratory. Sometimes, Curtis thought old Androka was a bit wacky—a scientist whose mind had been turned by the horror that had come to his country under the domination of the Nazi gestapo . At other times, the man seemed a genius. Perhaps that was the answer—a mad genius! if this might have been the source of Androka's zone of silence, when behind. Curtis was studying the wreckage of the wireless station, wondering fumbling at the neck of his slicker. Rain was coursing down his white cheeks, streaking them with glistening furrows. Curtis closed the door and nodded toward the bent form of Zukor Androka, with a quizzical grin. "Old Czech-and-Double-Czech is working hard on his latest invention to pull Hitler's teeth and re-establish the Czech Republic!" Nelson had no answering smile, although there had been a great deal Androka decrees silence over the German airways! Try it! Try it, I say!" can enter or leave my zone of radio silence—of refracted radio waves, Curtis was the first to speak. "Your secrecy might well cost the United States navy one of its best light cruisers—and us our lives!" he said angrily. "We need that check Androka held out his palms helplessly. "I can do nothing. I have given orders to my assistant that he must keep two hours of radio silence! I winking at the two officers over Androka's discomfiture, and asked for numbers. Ignoring the gibbering Androka, who was wailing his has done something to the Curtis left him at it, and went to rejoin Androka in the cabin. He found the little inventor pacing up and down, shaking his fists in the air pausing every now and then to run his bony fingers through his tangled mop of gray hair, or to claw nervously at his beard. "You have seen a miracle, commander!" he shouted at Curtis. " My hopelessly." "Seems to me," Curtis said dryly, "this invention can harm your friends as much as your enemies." little over five feet. His voice grew shrill. "Wait! Just wait! There are other inventions to supplement this one. Put them together, and they will defeat the Nazi hordes which have ravaged my country!" Curtis was a little shocked by the hatred that gleamed in Androka's eyes, under their bushy brows. There was something of the wild animal with this radio silence?" A far-away look came into Androka's eyes. He did not seem to hear two daughters. If the gestapo knew what I am doing, all of them would be better dead. You understand—better dead?" Curtis said: "I understand." "And if the Nazi agents in America knew of the islet from which my zone of silence is projected—" Androka paused, his head tilted to one side, Curtis' ears with a note of impending tragedy. "Breakers ahead!" And then he became aware of a deadly stillness. A vast wall of silence Somehow, Curtis' mind flashed to the stories he'd heard of the forts of the Maginot Line, and of other forts in Holland and Belgium that had fallen before the early Nazi blitzkrieg, when their defenders found themselves struck numb and helpless by a gas that had been flooded into the inner compartments of their strongholds. There were those who said it was the work of sappers who had tunneled under the foundations, while others laid the induction of the gas to Fifth Column traitors. There were a hundred more or less plausible explanations— it swept over his brain— He felt something strike the side of his head, and realized that he had stood his fellow conspirator Bos'n's Mate Joe Bradford, also wearing a gas mask. before the ship's rid of that damn gas!" Bradford shook his head in disagreement. "The old geezer claims he's got a neutralizing chemical in one of them tanks of his that'll clear everything up inside half an hour." "I'd rather get along without Androka, if we could!" Nelson muttered. "He's nothing but a crackpot!" "It was a crackpot who invented the gas we used to break up the Maginot Line," Bradford reminded him. "It saved a lot of lives for the Fuehrer the United States—of German parents, who had been ruined in the First World War. My mother committed suicide when she learned that we were penniless. My father—" He paused and cleared his throat. " Your father?" the German officer prompted, dropping into accented English. "Your father?" "My father dedicated me to a career of revenge—to wipe out his wrongs," Nelson continued. "If America hadn't gone into the First World War, he wouldn't have lost his business my mother would still be living. When he joined the Nazi party, the way became clear to use me—to educate me in a military prep school, then send me to Annapolis, for a career in the United States navy—and no one suspected me. No "Maybe Curtis'll find out his suspicions were justified," Nelson said bitterly. "But it won't do Curtis any good—a commander who's lost Androka had brought aboard the strange figure of Professor Zukor Androka! That zone of silence cut us off completely." "Hereafter," Brandt said solemnly, "the zone of silence vill be Androka's vich vill be even more useful vhen ve come to cut the "What's the idea?" capturing a United States navy cruiser." "There are other things Germany needs desperately on board the Carethusia Carethusia is taking over." "Can we trust Androka?" Nelson asked, with a sudden note of suspicion "Yes," Brandt assured him. "Of all men—we can trust Androka!" foreigners whom it chooses as its agents," Brandt pointed out. "Androka has a daughter and other relations in Prague. He knows that if anything misfires, if there is the slightest suspicion of treachery on his part, his daughter and the others will suffer. Androka's loyalty is assured!" Nelson turned to watch the forward fighting top of the Comerford . The masked German seamen were installing some sort of apparatus room that served as Androka's laboratory and workshop. to rid the below-decks atmosphere of the lethal gas that had overcome the Comerford's out his hand. "Congratulations, Herr Kommander Nelson!" he said. "Ve have stolen one of the United States navy's newest and fastest cruisers!" He made a Prosit! " he his limbs were stiff and numb. His nose and throat felt parched inside, as if a wave of searing heat had scorched them. According to his last calculations, the Comerford The words struck Curtis with the numbing shock of a blow on some nerve center. For the first time, he realized fully the tragedy that had swept down on him. He had lost his ship—one of the United States navy's fastest and newest small light cruisers—under circumstances which smelled strongly of treachery and sabotage. As he thought back, he realized that he might have prevented the loss, if he had been more alert, more suspicious. For it was clear to him now that the Comerford had been deliberately steered to this place that the men who had seized her had been waiting here for that very purpose. puzzle—Androka's zone of silence

<question>:
What is Androka’s motivation for using the zone of silence?

<options>:
A He is helping the Nazi war effort
B He is helping the American Navy.
C He is doing Bob Curtis a favor by helping his ship be the most successful in the Navy.
D He is planning revenge against the Nazis for harming his family.

<answer>:

A