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

<passage>:
Radio is an absolute necessity in modern organization—and particularly in modern naval organization. If you could silence all radio—silence of that sort would be deadly! [Transcriber's Note: This etext was produced from Astounding Science-Fiction April 1942. Extensive research did not uncover any evidence that still some unconscious men to be revived. In a sheltered cove among the scene with a ghostly radiance. The men of the the U.S. copyright on this publication was renewed.] to the door, paused there, and flung a backward glance at the man in the cabin with him—Zukor Androka, the elderly Czech scientist, a guest of the United States navy, here aboard the cruiser Comerford was also missing! With the coming of dawn, a little exploration revealed that the Comerford's crew was marooned on an islet, about a square mile in area that they had been put ashore without food or extra clothing or lips relaxed in a faint smile. from Norfolk. With him came a boatload of scientific apparatus and equipment, including a number of things that looked like oxygen tanks, radio station on a high promontory on the north shore of the islet. demolished, in a small, timbered hollow—a well-hidden spot invisible from the air, unless one were flying very low 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 which the recent inhabitants of the islet couldn't afford to leave a place where two Another had found the remains of tents and log cabins, recently like a stinging wet lash. Overhead, the sky was a storm-racked mass of clouds, broken in one spot by a tiny patch of starlit blue. him. It was the Czech Republic!" Nelson had no answering smile, although there had been a great deal of good-natured joking aboard the and islets—" "Radio?" repeated the little Czech, thrusting his face between the other two, in his independent fashion that ignored ship's discipline. that had recently been established to insure safety to naval vessels, but there was no answer on any of the bands—not even the blare of a high-powered commercial program in the higher reach, nor the chatter of ships or amateurs on the shorter. "Dead!" Androka muttered, with a bitter laugh. "Yet not dead, have shattered them around your ship, just as I can eventually shatter them all over Central Europe! For the next two hours, no radio messages can enter or leave my zone of radio silence—of refracted radio waves, set up by my little station on one of the neighboring islets!" There was a long pause, while commander and navigator stared at him. Androka had arrived on board the by radio at once! If you're not talking nonsense, call off your dogs till we learn just where we are!" Androka held out his palms helplessly. "I can do nothing. I have given —" "U. S. Cruiser numbers. Ignoring the gibbering Androka, who was wailing his disappointment that messages had penetrated his veil of silence, they done something to the ether. The set seems O. K." "You have seen a miracle, commander!" he shouted at Curtis. " My miracle! My invention has shattered the ether waves hereabouts hopelessly." "Seems to me," Curtis said dryly, "this invention can harm your friends 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!" eyes, under their bushy brows. There was something of the wild animal their picked up, and was being relayed all over the ship. The words struck on Curtis' ears with a note of impending tragedy. ship. The was shrouded in a huge pall of yellowish-gray mist, and more of it was coming up from below—from ventilators and hatchways and themselves struck numb and helpless by a gas that had been flooded into the inner compartments of their strongholds. Fifth Column traitors. There were a hundred more or less plausible explanations— The vapor clouds that enveloped the Comerford All about the deck lay the forms of unconscious seamen, suddenly deck—forms that looked like creatures from another world, but he recognized them for what they were—men wearing gas masks. Voices droned all around him in mumbling confusion—guttural voices English now and then, mixed in with a flood of Teuton phonetics. Two words, in particular, registered clearly on his mind. One was " " the other was "convoy." But gradually his eardrums began to throb, as if someone were pounding on them from the inside. He couldn't get his breath figures moving about the decks, descending companionways—like goblins from an ancient fairy tale or a modern horror story. Nelson looked like "I don't speak any German," he explained. "I was born and educated in 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. " 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 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 one—" men—officers, seamen, mechanics, radio men, technical experts, all German naval reservists living in the United States, who've been sent here secretly, a few at a time, during the past six weeks!" with strange-looking radio equipment, and more gas tanks like those Androka had brought aboard the Comerford with him, and dynamos and batteries that looked like something out of a scientific nightmare. And bustling all over the place, barking excited commands in German, projected from the Comerford and ve have another invention of out of her convoy." "The Carethusia "What's the idea?" "Her cargo," Brandt explained. "It iss more precious than rubies. It "Boarts?" Nelson repeated. "What are they?" imperfectly crystallized stones, but far more valuable to us than flawless diamonds from Tiffany's on Fift' Avenue. They are needed for making machine tools. They come from northern Brazil—and our supply is Carethusia ," Brandt explained. "Vanadium and nickel and hundreds of barrels of lard oil for machine-tool lubrication. Our agents have been Carethusia is taking over." "Can we trust Androka?" Nelson asked, with a sudden note of suspicion in his voice. "But he's a Czech," Nelson argued. "The gestapo takes care of Czechs and Poles and Frenchmen and other 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, . The masked German seamen were installing some sort of apparatus up there—a strange-looking object that looked something like an old-fashioned trench mortar, and which connected with cables to the 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 American crew. as if a wave of searing heat had scorched them. According to his last calculations, the Comerford off the Maine coast. This probably was one of the islets of that region, or it might be the mainland. which smelled strongly of treachery and sabotage. As he thought back, he realized that he might had been deliberately steered to this place puzzle—Androka's zone of silence the bearings given by radio Navigating Officer Nelson's queer conduct. They were all part of a

<question>:
Where do the creatures from another world come from?

<options>:
A The Carethusia
B The Sea
C Germany
D An alien world

<answer>:

C