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

<passage>:
life traces on that little moon, but it would be a lively place. So they skipped several steps in the procedure. Positive over most of the surface. There several tests and went to the cognition scanner. Would it show Thought on the body? Naturally they did not get results at once, nor did they expect to it required a fine adjustment. But they were disappointed that they found nothing for several hours as they hovered high over the rotation. Then before it's back in our ken if we let it go now." "Let's lock on this one and finish the scan. Then we can do the rest of the world to make sure we've missed nothing," said Stark. There was one more test to run, one very tricky and difficult of analysis, that with the Extraordinary Perception Locator. This was designed simply to locate a source of superior thought. But this might be so varied or so unfamiliar that often both the machine and the when turned on the inventor himself, bad blood developed between machine and man. Glaser knew that he had The machine replied, with such warmth that its relays chattered, that And there was no denying that the Extraordinary Perception Locator (or Positive on a Positive on ninety per cent of the acknowledged superior minds of the Earth. In space it had been a on a two-inch-long worm, only one of them out of billions. For the countless identical worms no trace of anything at all was shown by the test. individual, though this could not be certain) and got very definite action. Eppel was busy. The machine had a touch of the ham in it, and assumed an air of importance when it ran these tests. Finally it signaled the result, the most exasperating result it ever of the shoulders in a man. They called it the "You tell me "Scan the remainder of the world, Steiner," said Stark, "and the rest from the thoughtful creature?" "No. The rest of the world may be dangerous. There must be a reason So they all, except Steiner, went off to their bunks then: Stark, the Dawn did not come to the moon-town. The Little Probe hovered stationary in the light and the moon-town came up under the dawn. Then the Probe track of the minds. There's nothing but a meadow and some boscage, a "Keep on towards the minds," said Stark. "They're our target." Earth-people. But with a difference. Where is that bright light coming "I don't know, but they're right in the middle of it. Land here. We'll "Talk to them, Father Briton," said Stark. "You are the linguist." "Howdy," said the priest. He may or may not have been understood, but the two of them smiled at "Ha-Adamah," said the man. It may be that the shining man frowned momentarily at this woman smiled, proving that she was human. named hoolock." wouldn't have a drink on you for a tubful of thirsty travellers, would "Ah—I see." But the crew all drank of the fountain to be sociable. It was water, the first water ever made. "What do you make of them?" asked Stark. "Human," said Steiner. "It may even be that they are a little more than human. I don't understand that light that surrounds them. And they seem "And very little else," said Father Briton, "though that light trick does serve a purpose. But I'm not sure they'd pass in Philadelphia." "Talk to them again," said Stark. "You're the linguist." "That isn't necessary here, Captain. Talk to them yourself." "Are there any other people here?" Stark asked the man. "The two of us. Man and woman." The captain was a little puzzled by this, but he went on doggedly: "Ha-Adamah, what do you think that we are? Are we not people?" Engineer. He is named Flunky." "But are we not people?" persisted Captain Stark. "No. We are the people. There are no people but two. How could there be going to prove him wrong? But it does give you a small feeling." "Can we have something to eat?" asked the Captain. will want to sleep on the grass. Being not of human nature (which does They wandered about the place, but they were uneasy. There were the animals. The lion and lioness were enough to make one cautious, though they offered no harm. The two bears had a puzzling look, as though they wanted either to frolic with you or to mangle you. "If there are only two people here," said Casper Craig, "then it may be that the rest of the world is not dangerous at all. It looked fertile those rocks would bear examining." "Flecked with gold, and possibly with something else," said Stark. "A haven't yet tried the—" and he stopped. "If you're thinking what I'm afraid to think," said Gilbert, "then it will be the test at least: whether we're having a pleasant dream or whether this is reality. Go ahead and eat one." "Ask him first. You ask him." "Well, the analogy breaks down there," said Stark. "I was almost beginning to believe in the thing. But if it isn't that, then what. "Of course they do. You know that as well as I." "I was never a believer. But would it be possible for the exact same It was the pomegranate tree, and he was warning Langweilig away from it. did understand the answer, however." "And do you think that you will ever die?" "To die I do not understand. I am taught that it is a property of "And are you completely happy here?" "Perfectly happy according to my preternatural state. But I am taught that on at least one other unfortunate world it has actually been lost." "Yes, there is a question that will settle it. Adam, old man, how about a game of checkers?" "This is hardly the time for clowning," said Stark. "I'm not clowning, Captain. How about it, Adam? I'll give you choice of colors and first move." "No. It would be no contest. I have a preternatural intellect." and have a go at it." "No. It would be no contest. I would not like to humble you." "What is there, Adam?" asked Captain Stark. They learned no more of the real nature of the sphere in their time there. Yet all but one of them were convinced of the reality when they left. And they talked of it as they took off. perfection. "So much for that. Now to business. Gilbert, take a gram: Ninety names were "Snake-Oil Sam," spoke to his underlings: "You are a goof, and therefore perfect for the part. I was in show pomegranate. People aren't becoming any smarter—but they are becoming better researched, and they insist on authenticity. "This is still a perfect come-on here. There is something in human whoop and holler to their neighbors to come in droves to spoil and mar a big-maned lion to lie down with the lamb." "I know it, Eve. The lion is a very important prop. Maybe one of the Casper Craig was still dictating the gram: neighbors. A completely planned globular settlement in a near arm of "And you had better have an armed escort when you return," said Father "Why in cosmos would we want an armed escort?" "It's as phony as a seven-credit note!" "You, a man of the cloth doubt it? And us ready skeptics convinced by our senses? Why do you doubt?" "It is only the unbelieving who believe so easily in obvious frauds. Theologically unsound, dramaturgically weak, philologically impossible, zoologically rigged, salted conspicuously with gold and shot through with anachronisms. And moreover he was afraid to play me at checkers." "What?" "If I have a preternatural intellect I wouldn't be afraid of a game of was just that he chose not to make our acquaintance personally." "They looked at the priest thoughtfully. "How?" "All the time we were there the woman did not speak."

<question>:
What was thought to be used as an indication to settle the confusion between the crew and the two humans in moon-town?

<options>:
A An inquisition about knowledge
B A game of checkers
C A contest of preternatural intellect
D A physical test

<answer>:

B