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

<passage>:
That's just line! Is Evans—?" Some men just haven't got good sense. They just can't seem to learn the most fundamental things. Like when there's no use trying—when it's time to give up because it's hopeless.... Evans was carrying a block of ice into the tractor when he saw the "A Welshman takes a lot of killing," Evans answered. "... And I don't know how long I sat there after I found the water." He looked at the Goldburgian device he had made out of wire and tubing. all of 'em. "The idea didn't come all at once, it took a long time for me to remember that water is made out of oxygen and hydrogen. When I remembered that, of course, I remembered that it can be separated with electricity. So I built this thing. "It runs an electric current through water, lets the oxygen loose in the room, and pipes the hydrogen outside. It doesn't work automatically, of Evans, who had no watch, thought of the time as a quarter after course, so I run it about an hour a day. My oxygen level gauge shows how Evans was a prospector, and like all prospectors, a sort of jackknife "I don't need rescuing, man," Evans said. claim." "Claim?" "Sure, man, I've thousands of tons of water here. It's the richest mine on the Moon!" THE END make it. By careful rationing, he could probably stretch his food out to more than a month. His drinking water—kept separate from the water in the reactor—might conceivably last just as long. But his oxygen was too carefully measured Evans was about three hundred miles east of Williamson Town, the site of dark again, and the search for him, if it ever began, could not begin for thirteen more days. At the earliest it would be eight days too late. "Well, man, 'tis a fine spot you're in now," he told himself. "Let's find out how bad it is indeed," he answered. He reached for the light switch and tried to turn it on. The switch was already in the "on" position. "Batteries must be dead," he told himself. "What batteries?" he asked. "There're no batteries in here, the power comes from the generator." "Why isn't the generator working, man?" he asked. He thought this one out carefully. The generator was not turned by the main turbine, but by a small reciprocating engine. The steam, however, came from the same boiler. And the boiler, of course, had emptied itself through the hole in the turbine. And the condenser, of course— "The condenser!" he shouted. He fumbled for a while, until he found a small flashlight. By the light of this, he reinspected the steam system, and found about three gallons of water frozen in the condenser. The condenser, like all condensers, was a device to convert steam into water, so that it could be reused in the water in the condenser began to boil. This boiling lowered the temperature, and the condenser demonstrated its efficiency by quickly freezing the water in the tank. Evans sealed the turbine from the rest of the steam system by closing operate the engine that drove the generator. The water would condense in the condenser, and with a little luck, melt the ice in there. Then, if the pump wasn't blocked by ice, it would return the water to the boiler. But there was no water in the boiler. Carefully he poured a cup of his drinking water into a pipe that led to the boiler, and resealed the pipe. He pulled on a knob marked "Nuclear Start/Safety Bypass." The water that he had poured into the boiler quickly turned into steam, and the steam turned the generator briefly. Evans watched the lights flicker and go out, and he guessed what the trouble was. "The water, man," he said, "there is not enough to melt the ice in the condenser." He opened the pipe again and poured nearly a half-gallon of water into used. It was one day's supply if used wastefully. It was ostentatious luxury for a man with a month's supply of water and twenty-one days to live. the boiler pressure began to fail, but the steam had melted some of the ice in the condenser, and the water pump began to function. "Well, man," he breathed, "there's a light to die by." potassium nitrate that anyone has ever seen. Man, it's a full inch across." All of these needed water to form, and their existence on the Moon puzzled him for a while. Then he opened the bag that had contained the the low-grade ores of uranium and vanadium, they need these things on Earth, but they can't get them as long as it isn't worth the carrying of them. And then, of course, there's the water we haven't got. We could afford to bring more water for more people, and set up more distilling plants if we had the money from the nickel. "Even though I say it who shouldn't, two-eighty a quart is too much to pay for water." "Have you seen our friend Evans lately? The price of chromium has gone profit." "He's out prospecting again. I don't expect to see him until sun-down." "Well, if I don't see him, you let him know about the chromium." "Anything to help another Welshman, is that the idea?" "Well, protection it is that a poor Welshman needs from all the English when Evans had quarried all the ice that was available in the cave. The thought grew on him as he worked that this couldn't be the only such a bubble. Suddenly, Evans noticed that the gauge on the oxygen tank of his suit was reading dangerously near empty. He turned back to his tractor, moving as slowly as he felt safe in doing. Running would use up so much, Evans had already shortened his life by several days. He resolved not to leave the tractor again, and reluctantly abandoned his plan to search for a large bubble. building, a gray concrete structure a quarter of a mile distant. "It would be pretty bad if they clogged up some night." was about half full, the water began to run nearly clear. An electric eye noted that fact and a light in front of Cade turned on. Cade threw the switch back the other way, and the relay in the reactor building They could see the trickle of water from the discharge pipe. The motor turned the valve back and forth in response to Cade's signals. "Is the light off?" Cowalczk asked. "No," Cade answered. "Water's stopped. Give us some pressure, we'll see if it holds." "Take her up to ... no, wait, it's still leaking," Cowalczk said. "Hold it there, we'll open the valve again." lost." "Two thousand?" Cade asked. "We only had seven hundred gallons reserve. How come we can operate now?" "We picked up twelve hundred from the town sewage plant. What with using the solar furnace as a radiator, we can make do." "Oh, God, I suppose this means water rationing again." "You're probably right, at least until the next rocket lands in a couple of weeks." is missing and presumed lost. Evans, who was apparently exploring Evans began his exploration on August 25th, and was known to be McIlroy has expressed a hope that Evans will be found before his oxygen runs out. Search parties have started from Williamson Town, but telescopic "Like as not, you're right," McIlroy replied, "but if I know Evans, he'd tells me that Evans will be found." "About Evans?" Phelps shook his head slowly. "Palomar called in a few this banker, who had never met Evans, was losing so much sleep about search. The director turned to ask Phelps about this fact, but the banker was

<question>:
What is Evans' primary dilemma?

<options>:
A He has a limited amount of time until the next meteor shower hits and permanently destroys his equipment
B In submitting a claim to the lava mine, he will attract violence from those desperate for water
C By entering into an unknown cave, he is possibly exposing himself to lava, which has the capacity to melt his space suit
D If he is to discover a new water source, he must utilize his low, existing source to find it

<answer>:

D