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 left the Earth with a wing and a prayer. Earth was so far away that it wasn't visible. Even the vast distance did not mean that isolation could endure forever. Instruments within the ship intercepted radio broadcasts and, within the hour, early TV signals. The history of the planet was it was not much out of the way to swing nearer Earth. For days the two within the ship listened and watched with little comment. They had to decide soon. "We've got to make or break," said the first alien. "You know what I'm in favor of," said the second. who had spoken first. "The place is a complete mess. They've never done anything except fight each other—and invent better weapons." "It's not what they've done," said Bal, the second alien. "It's what they're going to do, with that big bomb." bomb can destroy them. Without our help they may do just that." in everything they do." "It won't take much," said Ethaniel. "The wrong diplomatic move, or a trigger-happy soldier have to be deliberate. A meteor it as an all-out enemy attack." was such a planet as Earth." "Could you? Forget so many people?" "I'm doing it," said Bal. "Just give them a little time and they won't be here to remind me that I have a conscience." "My memory isn't convenient," said Ethaniel. "I ask you to look at them." intently. "Very much like ourselves," he said at last. "A bit shorter perhaps, and most certainly us. Is that what you wanted me to say?" "It is. The fact that they are an incomplete version of ourselves touches me. They actually seem defenseless, though I suppose they're not." "There is. We can give them their entire history. We can't begin to undo the effect of the "You can't tell," said Ethaniel. "We can look things over." authority do we have?" "Very little," conceded Ethaniel. "Two minor officials on the our people want," said Ethaniel. "And how long can Earth last? Ten years? Even ten months? The tension is building by the "What can I say?" said Bal. "I suppose we can stop and look them over. We're not committing ourselves by looking." They went much closer to Earth, not intending to commit themselves. For a day they circled the planet, avoiding radar detection, which for them was Finally Ethaniel looked up from the monitor screen. "Any conclusions?" showed that as far away as we were." "I know." "We also knew they could deliver by some sort of aircraft." "That was almost a certainty. upward. They either have or are near a primitive form of space travel." "Bad," said Ethaniel. "Sitting there, wondering when it's going to hit them. Nervousness could set it off." did you find out at your end?" "I realize that." "A flat yes or no," said Bal. "No. We can't help them," said Ethaniel. "There is nothing we can do for them—but we have to try." "Sure, I knew it before we and when we can't help them we they met again. In the meantime the ship moved much closer to Earth. They no longer needed instruments to see it. The planet revolved outside the visionports. the oceans cold. And it will be cold." "Yes. It's their winter." beings?" hundred years ago it might have worked. Today they have satellites. They are not primitives." "I suppose you're right," said Bal. "I did think we ought to "If we could I'd be all for it. But these people are rough and desperate. They wouldn't be Bal. "All right," said Ethaniel. "You take one side and I the other. We'll tell them bluntly what they'll have to do if they're going to survive, how they can keep their planet in one piece so they can live on it." "Can't help it. That's all we have time for." "Special instructions?" "None. We leave the ship here and go down in separate landing craft. You can talk with me any time you want to through our communications, but don't unless you have to." "They can't intercept the "They can't, and even if they did they wouldn't know what to do with our language. I want to talk things over." "I get it. Makes us seem better than we are. They think we know though we don't." "If we're lucky they'll think the planet below. "It's going to "I'm afraid not. The great are the ones we have to reach to "I know, they don't like their helped. We can't wait until it's over." "I'm aware of that," said Bal. and leave the ship up here with no one in it." "They can't touch it. No matter how they develop in the next hundred years they still won't be able to get in or damage it in about. Down there, alone." "I'll be with you. On the other side of the Earth." "That's not very close. I'd like it better if there were someone in the ship to bring it down in a hurry if things get rough. They don't think much of each other. I don't imagine they'll like aliens any better." "They may be unfriendly," Ethaniel acknowledged. Now he switched a monitor screen until "If it saves my neck I'm for the ship against the sun planet and light it up." "Say, pretty good," said Bal. "They can't imagine that we'd light up an unmanned ship," said should occur to them they'll have no way of checking it. Also, they won't be eager to harm us with our ship shining down on them." "That's thinking," said Bal, moving to the controls. "I'll move the ship over where they can see it best and then I'll light it up. I'll really light it up." "Don't worry about that. They'll see it. Everybody on Earth will see it." Later, with the ship in position, glowing against the darkness of space, pulsating with light, Bal said: "You know, pull it off. Lighting the ship may be just the help we need." "It's not we who need help, but the people of Earth," said Ethaniel. "See you in five days." With that he entered a small landing craft, which left a faintly luminescent Earth. As soon as it was of the planet. And the spaceship circled Earth, unmanned, blazing and pulsing with light. No star in the winter skies of the planet below of a star and brought near Earth to illuminate it. Never, or like it. In five days the two small landing craft that had left it arched up from Earth and joined the orbit of the large ship. The two small craft slid inside the large one and doors closed behind them. In a short time the aliens met again. "We did it," said Bal exultantly as he came in. "I don't know how we did it and I thought we were going to fail but at the last minute they came through." agreement they made isn't the best but I think it will keep them from destroying themselves." "It's as much as we can expect," said Ethaniel. "They may have small wars after this, but "Why?" "When I went out walking people stopped to look. Some knelt in the snow and called me an angel." "Something like that happened "I didn't get it but I didn't let it upset me," said Bal. "I smiled at them and went about my business." their paintings they had pictured "But you don't know what an angel is?" out. Some creature of their folklore like ourselves. Their legends are bound to resemble ours." "Sure," said Bal. "Anyway, peace on Earth." THE END Transcriber's Note: Amazing Science Fiction Stories

<question>:
Why do the aliens believe they have succeeded in saving Earth?

<options>:
A The humans did come to a formal agreement before the aliens left them.
B The humans realized they were not alone in the universe. They dropped all their petty differences to defend themselves against an alien invasion.
C The humans painted many pictures of the aliens to commemorate the historic event of first contact, a sign they will hold to the agreement made.
D The humans were kneeling before the aliens in deference, a sign that they will hold to the agreement made.

<answer>:

A