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

<passage>:
sag of the dust I learned to spot a passable crack, and tell it from an impassable cut. Time after time the Bugs ground to had no stomach for mysteries, vast or trifling, and there until we were sure the surface would carry the machines. It we slept in exhaustion. But it went smoothly, was cruel work at first. He talked too much, while we were resting or while we were driving wisecracks, witticisms, unfunny jokes that wore thin each stop, more reserved and apprehensive. I didn’t like it, but I figured that it would pass off after a while. I was apprehensive enough myself I just managed to hide it better. filters we would have been blinded as it was our eyes ached constantly and the skin on our faces itched and tingled at the end of an eight-hour trek. forehead were twisted and brown, with scars that were still he looked weary and immensely ugly. His cheeks and route and was almost out of sight in a cloud of ash when we heard a sharp cry through our earphones. and, for once, he didn’t have anything to say. It was the wreck gone. “Great balls of fire, man— where have you been hiding? We’ve been trying to contact you for months!” It looked the same, but every now and then it felt different. On two occasions I felt my wheels spin, with a howl of protest fingers were trembling. I gunned my motor and nothing happened. I could see the dull gray stuff seeping up around the hubs, thick and tenacious, splattering around in steaming gobs as the wheels spun. I knew what had happened the moment the details . Where did your equipment fall down? Where did you miscalculate? What were the trouble spots?” Baron jabbed a finger at Claney’s face. “That, for instance—epithelioma? Why? What was wrong with your glass? Your filters? We’ve got to know those things. If you can tell us, we can make it across where your attempt failed—” “It’s simple. We failed because it can’t be done. We couldn’t can blame the equipment or the men—there were flaws in both quarters—but we just didn’t know what we were fighting. It was the It was a grueling eight hours and we slept poorly. Back in that whipped us, that and the planet thought out of my mind. Sun I know now that they were a pair of idiots, starting off without a section of the fault like a ramp. Even as I watched it, I could feel the surface crust under the Bug trembling and saw the conditions, without any charts—they couldn’t have made years together up there doing some of the nastiest exploring since the Matto Grasso. Then he made the attempt on Vulcan and how he preferred a hot trek to a cold one any day of the “No, I mean real heat.” “What trip?” heat, just to have some joker come along, use your data and drum you out of the glory by crossing at perihelion forty-four days later? No, thanks. I want the Brightside without any nonsense about it.” He leaned across me eagerly. “I want to make it. Nobody had, since Wyatt and Carpenter disappeared. Mercury It would be a hellish trek. Only a few men had ever learned how hellish and they never came back to tell about it. It hold his observatory. He’d chosen a good location, too. On Mercury, the Brightside temperature hits 770° F. at perihelion and the Darkside runs pretty constant at -410° F. No permanent installation with a human crew could survive at either liable to get awfully uneasy and none of them can We had four Bugs, three of them the light pillow-tire models, with special lead-cooled cut-in engines when the heat set in, line? We’ll need plenty of both.” “Have you ever worked with him?” I asked. “No. Are you worried?” be active. Seismograph tracings suggest a lot of activity in that region, getting worse down toward the equator—not only volcanic, but sub-surface Stone nodded. “Sanderson told me there was probably constant surface activity.” The Major shrugged. “Well, it’s treacherous, there’s no It seemed that the more we considered the problem, the localized. But there were problems of atmosphere on Brightside, as well. There was an atmosphere and a constant atmospheric 2 , and nitrogen, and traces of other heavier gases. There was also an abundance of sulfur condensed, carrying enough volcanic ash with it for Sanderson to estimate the depth and nature of the surface upheavals on sleepy, almost indolent, but capable of abrupt alertness. running the final tests on the pressure suits. That evening, reliable at first glance. Anyway, personality problems weren’t our big problem right then. worried us first and route one had an inner lining of a fiberglass modification, to avoid the clumsiness of asbestos, and carried the refrigerating unit the two layers. Warning thermocouples, of course—at 770 degrees, it wouldn’t take much time to fry us to cinders if the suits failed somewhere.” “How about the Bugs?” “They were insulated, too, but we weren’t counting on “We’d be in and out of them too much. They gave us mobility We just didn’t quite end on schedule, that was all. But I’m when we started, twice the size it appears on Earth. Every day seventy miles a day, no matter how hot it became, no matter what terrain we had to cross. Detours would be dangerous and time-consuming. Delays could cost us our lives. We all knew that. detail work. We don’t need to worry about the major topography. It’s the little faults you “But why not? We could save ourselves days!” It was hot. If I forget everything else about that trek, I’ll break, hotter and hotter with every mile. We knew that the first few days would be the easiest and we were rested and Even at only 30 per cent Earth gravity they were a strain on the heat so much those first days out. We it. The refrig units kept our skins at a nice comfortable seventy-five some nerve pathways got twisted up, somehow. We poured sweat as if we were in a superheated furnace. We drove eight hours and slept five. When a sleep period a light aluminum sun-shield and lay out in the dust and rocks. The sun-shield cut the temperature down sixty or seventy bulk gelatin, vitamins. The Major measured water out with an iron hand, because we’d have drunk ourselves into nephritis in a week otherwise. We were constantly, unceasingly thirsty. Ask the physiologists reasons—but all we knew, or cared about, was that it happened to be so. We didn’t sleep the first few stops, as a consequence. Our eyes burned in spite of the filters and we had roaring headaches, but we couldn’t sleep them off. We sat around looking After a few driving periods, I began to get my bearings at the wheel. We were moving down into desolation that made the air was filled with a barely visible yellowish mist of sulfur and sulfurous gases. the challenge was so powerful you could almost feel it. No one could throw up to us, at the most difficult time possible. before, except for that Sun. We’d fought absolute cold before east. This range had shown no activity since the first landing on Mercury forty years before, but beyond it there were active cones. Yellow fumes rose from the craters constantly their sides were shrouded with heavy ash. We couldn’t detect a wind, but we knew there was a hot, sulfurous breeze sweeping in great continental tides across the face of the planet. Not enough for erosion, though. The craters rose up out of jagged gorges, huge towering spears of rock and dust—silicates and salts, pumice and limestone and granite ash, filling crevices and declivities—offering a soft, treacherous surface for the Bug’s pillow tires. I learned to read the ground, to tell a covered fault by the

<question>:
What wasn't an issue their bodies were going through?

<options>:
A dehydration
B malnutrition
C headaches
D irritation

<answer>:

B