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

<passage>:
They were still separated, two on one side of the airlock, two on the other. melting, yes. Melting down at the bottom a little. Now it's falling over to one side and laying on the air tank. The air tank is getting red, too. I'm afraid ... it's weakening it.... Redder. Oh, oh." "Maybe," Lt. Chandler said, "it's buried too deep." "Maybe so," Major Winship said. "But we can't have the dome fall down around all our ears." He stood. "Whew! You guys stay put." closing the door behind him. The darkness slowly filled with air, and the temperature inside the suit declined steadily. At the proper moment off balance. He stumbled against the table and ended up seated beside the radio equipment. The ground moved again. "It's—" completely. It then abated to something in excess of normal. "I guess I was just—" Major Winship began. "Oh, hell! We're losing pressure. Where's the markers?" "By the lug cabinet." and plastered it against a riveted seam of the dome. It pulsed as though it were breathing and then it ruptured. had cut in automatically with the pressure drop. "You guys wait. It's on your right side, midway up. I'll try to sheet it." He moved for the plastic sheeting. "We've lost about three feet of calk out here," Capt. Lawler said. "I can see more ripping loose. You're losing pressure fast at this rate." 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 sprung a little, and I can't get it to conform over the rivet heads." There was a splatter of static. "Damn!" Major Winship said, "they should have made these things more to slide downward, then it fell away completely and lay limply on the floor. "Come on in," he said dryly. With the four of them inside, it was somewhat cramped. Most of the five hundred square feet was filled with equipment. Electrical cables trailed loosely along the walls and were festooned from the ceiling, space was more restricted than in a submarine, with the bunks jutting out from the walls about six feet from the floor. Lt. Chandler mounted one of the bunks to give them more room. "Well," "Oh! Excellent, very good. Any damage, Major?" much regret this. Very much so. I am very distressed. Depressed. After this leak fixed. Skip, can you get the calking compound?" wall. He traced the leak with a metallic finger. "How does this stuff work?" Capt. Lawler asked. They huddled over the instruction sheet. "Let's see. Squeeze the tube until the diaphragm at the nozzle ruptures. Extrude paste into seam. Allow to harden one hour before service." "The only way you can check is to extrude it," Lt. Chandler said, "and if it does extrude, you've ruined it." something else goes wrong." "As long as they'll loan us the calking compound," Capt. Wilkins said. "You got any concentrate? I'm empty." "I'll load you," Capt. Wilkins volunteered wearily. It was an awkward operation that took several minutes. Capt. Wilkins cursed twice during the operation. "I'd hate to live in this thing for any period." better than three thousand square feet in the main dome and better than twelve hundred square feet in each of the two little ones. And there's wooden desk. And a chair. A wooden chair. Everything big and heavy. Everything. Weight, hell. Fifty pounds more or less—" "They've got the power-plants for it." "That's the thing. That's the thing that gripes me, know what I mean? It's just insane to send up a heavy wooden desk. That's showing off. Like a little kid." equipment around until the emergency jacks were accessible. He unearthed the appropriate cable and began unscrewing the exterior Leak? repaired?" "The leak has not yet been repaired. Over and out." Capt. Lawler and Lt. Chandler returned with the calking compound. It was a fifty-five gallon drum. The airlock to Freedom 19 was open. "What is that "That," said Capt. Lawler, "is the calking compound." Capt. Lawler and Lt. Chandler came inside. Capt. Wilkins mounted a bunk. "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 55-gallon drums of it." "Oh, my," said Capt. Wilkins. "I suppose it's a steel drum. Those things must weigh...." "Actually, I think you guys have got the general wrong," Capt. Lawler scales." "Well, anyway," Lt. Chandler continued, "he told us just to mix up the whole fifty-five gallon drum. There's a little bucket of stuff that goes in, and it's measured just right. We can throw away what we don't need." calking compound. Those people are insane." the mixer out there." "We're going to have to bring the drum in," Capt. Wilkins said. "Well," said Capt. Lawler, "that will make it nice and cozy." It took the four of them to roll the drum inside, rocking it back and forth through the airlock. At that time, it was apparent the table was interposing itself. Lt. Chandler tried to dismantle the table. "Damn these suits," he said. "You've got it stuck between the bunk post." "I know that." "I don't think this is the way to do it," Major Winship said. "Let's back the drum out." Reluctantly, they backed the drum out and deposited it. With the aid of Capt. Lawler, Lt. Chandler got the table unstuck. They passed it over carried it around the drum of calking compound and set it down. It rested uneasily on the uneven surface. "Now, let's go," said Major Winship. Eventually, they accomplished the moving. They wedged the drum between the main air-supply tank and the transmitter. They were all perspiring. "It's not the weight, it's the mass," said Capt. Wilkins brightly. "The hell it isn't the weight," said Lt. Chandler. "That's heavy." "With my reefer out," said Major Winship, "I'm the one it's rough on." "It's the salt." With the drum of calking compound inside, both Capt. Lawler and Lt. Chandler retreated to the bunks. Capt. Wilkins maneuvered the mixing attachment. "I feel crowded," he said. "Cozy's the word." "Watch it! Watch it! You almost hit me in the face plate with that!" "Sorry." "Now what, Skip? The instructions aren't in English." "You're supposed to dump the bucket of stuff in. Then clean the area thoroughly around the leak." "No," Capt. Lawler said. "It sets by some kind of chemical action. harder than a rock! It is an epoxy! Let's get out of here." temporarily engaged with each other. Movement was somewhat ungainly in the space suits under the best of conditions, and now, with the necessity for speed, was doubly so. The other two crashed into them from behind, and they spewed forth from the dome in a tangle of arms and legs. like shrapnel." They obeyed. "What—what—what?" Capt. Lawler stuttered.

<question>:
What goes wrong with the calking compound?

<options>:
A It ends up being epoxy resin, which activates and starts melting.
B They're unsure how to read the instructions and mix it incorrectly.
C It's the wrong substance. Because of the language barrier, the Russians set them off with the wrong barrel.
D The barrel doesn't fit in the space they need it to.

<answer>:

A