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

<passage>:
The enemy was friendly enough. scheduled for the following morning. Major Winship, after receiving the message, discussed precautions with the three other Americans. Next morning, before the sunlight exploded, the four of them donned lay in harsh contrast, their edges drawn with geometric precision. Major Winship attempted unsuccessfully to communicate with Base Gagarin. "Will you please request the general to keep us informed on the progress of the countdown?" "Is Pinov," came the reply. "Boom! Boom!" said Major Winship in exasperation. "Boom—boom!" said Pinov. "Oh, nuts." Major Winship cut out the circuit. "They've got Pinov on emergency watch this morning," he explained to the other Americans. "The one that doesn't speak English." "He's done it deliberately," said Capt. Wilkins, the eldest of the four Americans. "How are we going to know when it's over?" No one bothered to respond. They sat for a while in silence while the shadows evaporated. One by one they clicked on their cooling systems. Major Winship shifted restlessly. "My reefer's gone on the fritz." Perspiration was trickling down his face. "Maybe," Lt. Chandler said, "it's buried too deep." "Maybe so," Major Winship said. "But we can't have the dome fall down "Charlie! Charlie!" "I'm okay," Major Winship answered. "Okay! Okay!" "It's—" "Okay," Major Winship said. "We told them this might happen," he added bitterly. There was a wait during which everyone seemed to be holding their Major Winship whinnied in disgust. " Nyet! " he snarled. To the other Americans: "Our comrades seem unconcerned." "Tough." They began to get the static for the first time. It crackled and "Well," Lt. Chandler commented, "even though we didn't build this thing to withstand a moonquake, it seems to have stood up all right." "I guess I was just—" Major Winship began. "Oh, hell! We're losing pressure. Where's the markers?" Major Winship moved quickly to cut out the emergency air supply which had cut in automatically with the pressure drop. "You guys wait. It's Major Winship pressed the sheeting over the leak. "How's that?" "Not yet." "I don't think I've got enough pressure left to hold it, now. It's There was a splatter of static. "Damn!" Major Winship said, "they should have made these things more flexible." "Still coming out." "Major Winship! Hello! Hello, hello, hello. You A Okay?" "This is Major Winship." "Oh! Excellent, very good. Any damage, Major?" "Little leak. You?" strongly, Major." "You did this deliberately," Major Winship said testily. "No, no. Oh, no, no, no, no. Major Winship, please believe me. I very much regret this. Very much so. I am very distressed. Depressed. After repeatedly assuring you there was no danger of a quake—and then to "Just leave us alone, thank you," Major Winship said and cut off the communication. "That's nice," Lt. Chandler said. "I'll be damned surprised," Major Winship said, "if they got any seismic data out of that shot.... Well, to hell with them, let's get hear anything without any air." Major Winship looked at the microphone. "Well, I'll just report and—" He started to pick up the microphone and reconsidered. "Yes," he said. "That's right, isn't it." service." Major Winship said dryly, "Never mind. I notice it hardens on contact with air." "How're the other ones?" asked Major Winship. Lt. Chandler turned and made a quick examination. "Oh, they're all hard, too." "The only way you can check is to extrude it," Lt. Chandler said, "and if it does extrude, you've ruined it." "That's that," Major Winship said. "There's nothing for it but to yell help." II something else goes wrong." "As long as they'll loan us the calking compound," Capt. Wilkins said. "Yeah, yeah," Major Winship said. Winship said. "I don't see how they can manipulate those bulky pieces of junk around." They ate. "They've got the power-plants for it." "Do you think he did that deliberately?" Major Winship asked. "I think he's trying to force us off. I think he hoped for the quake. Gagarin's built to take it, I'll say that. Looks like it, anyhow. You don't "You told me," Capt. Wilkins said. After a moment, Major Winship said bitterly, "To hell with the Russian engineer." "If you've got all that power...." unearthed the appropriate cable and began unscrewing the exterior plate to the small transmitter-receiver set on Major Winship's back. Eventually, trailing wires, Major Winship was coupled into the network. "Okay?" American moonbase." At this point, Major Winship observed for the first time that he was "Just a moment." "Is everything all right?" Major Winship was squirming nervously, obviously perturbed. "A-Okay," he said. "Just a moment." "What's wrong?" came the worried question. In the background, he heard someone say, "I think there's something wrong." Capt. Wilkins peered intently. Major Winship contorted his face in a Air, Major Winship said silently. Leak? "All right? Are you all right?" "We're all right. A-Okay." Major Winship, mindful of the extent of his potential audience, took a deep breath. "Earlier this morning, the Soviet Union fired an underground atomic device for the be able to deliver replacements in about ten days." "I will forward a coded report on the occurrence," Major Winship said. "Let us hear from you again in ... about three hours. Is the leak repaired?" transmitter. "Wow!" said Major Winship when he was once more in communication. "For a moment there, I thought...." Winship, squinting out into the glaring sunlight. "That," said Capt. Lawler, "is the calking compound." "You're kidding," said Capt. Wilkins. "Why didn't you just borrow a cupful?" Major Winship said sarcastically. "It's this way," Lt. Chandler said. "They didn't have anything but said. "He was out, himself, to greet us. I think he was really quite upset by the quake. Probably because his people had misfigured so bad." "He's too damned suspicious," Major Winship said. "You know and I know why they set that blast off. I tried to tell him. Hell. He looks at me like an emasculated owl and wants to know our ulterior motive in trying to prevent a purely scientific experiment, the results of which will be know that." "I don't think this is the way to do it," Major Winship said. "Let's forgotten how much sweat stings in the eyes." "It's the salt." "Speaking of salt. I wish I had some salt tablets," Major Winship said. "I've never sweat so much since basic." "Want to bet Finogenov hasn't got a bushel of them?" "No!" Major Winship snapped. With the drum of calking compound inside, both Capt. Lawler and Lt. thoroughly around the leak." "With what?" asked Major Winship. "Huh?" "Out! Out!" Major Winship, Lt. Chandler, and Capt. Lawler, recognizing the sense of necessity for speed, was doubly so. The other two crashed into them

<question>:
What reason would the Russians have to drive the Americans off?

<options>:
A The two stations are much too close to one another.
B They want the sole ability to conduct research on the moon.
C They know the Americans are ahead of them technology-wise.
D They don't trust the Americans, the same way Winship distrusts them.

<answer>:

B