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

<passage>:
world requires for a healthy and comfortable life cannot be provided control. "And it is true that we can always exterminate any planet that refuses to obey the just and legal orders of its Viceroy. So we achieve toward the palace of Viceroy the unfamiliar planet. away from us, through trickery, were unable to take over the Sectors we control. We are still Earthlings, that is." stalemate. You've got the idea that, with our help, you can conquer planets without the necessity of destroying them, and thereby If they carried out the threats of their present attitude, Earth would have to send Marshall to replace him. And if Crownwall couldn't do at the Viceroy's gesture. take over number one spot from blockade without any trouble. Our instruments didn't even wiggle when you landed here on my capital gate of the palace. His manner but he assumed that his silence the Viceroy's Palace?" asked side, you have the power to destroy our only planet at any time. That is certainly adequate security for our own good behavior and sincerity. "It is impossible for us of Earth to destroy all of your planets. As Seventy Suns, Viceroy of the you have said, there are more planets that belong to you than there are human beings on Earth. But there is a way for us to be reasonably "Just tell him that a man has arrived from Earth to talk to him. He'll summon me fast enough. you cannot prevent—to send one of those bombs here to destroy this planet. "And if you try to move anywhere else, by your clumsy distorter drive, we can follow you, and destroy any planet you choose to land on. You would not get away from us. We can track you without "We wouldn't use the bombs lightly, to be sure, because of what would happen to Earth. And don't think that blowing up our planet would save you, because we naturally wouldn't keep the bombs on said to Crownwall. "Follow me. His froze into immobility at the sides of the entrance. Crownwall stamped out his delay. Meanwhile, I see no reason "Nor do I," consented Crownwall. His Effulgence wiggled his tentacles. "It's customary to genuflect when you enter the Viceroy's presence," Earthling. I suppose we can expect Viceroy languidly. He twitched a tentacle in a beckoning gesture. "Come closer, Earthling. I bid you welcome to my capital. I have been that I would be the one to make the trip here. Even if you could spy through buildings on Earth from space, which I doubt, your Crownwall nodded. "I don't see why not. Well, then, let me tell you that we don't travel in space meant was that I expected someone from Earth to break through our blockade and come here. Most of my advisors—even Ggaran here—thought it couldn't be done, but instruments. Instead, we travel in time. Surely any race that has progressed as far as your own must at all. That's why I didn't show up on any of your long-range detection Crownwall. "If you wanted someone from Earth to come here to see you, why did you put the cordon around Earth? And why did you drop a planet-buster in the Pacific Ocean, and tell us that it was triggered to go off if we tried to use told you that Earthlings were unbelievably Earth as the spatial referent, to move with Earth a little more than a third of the way around this spiral nebula that is our Galaxy. your presence here would be useless billions of you squatting on one minor planet, we still need each other. Together, there is nothing to move in time, the whole Galaxy moved spatially with reference to stalks in amusement. "I'm Viceroy tube with his eating orifice. "You upstart Earthlings are a strange When you showed up in the spaceways, it was decreed that you had to be stopped at once. There was even serious discussion of destroying Earth out of hand, while it is still possible. "Your silly little planet was carefully of the Emperor. So we let you too long—but no matter. "You Earthlings, in defiance of all expectation and all reason, have exploded into space. You have developed space of time. But even that isn't the most disconcerting item of your development. As an Earthling, you "When the Viceroy of the Seventy Suns," said the Viceroy of the without requesting permission, and in space, about forty thousand kilometers above the Earth. It had been manned by a dozen adventurous people, captained by Crownwall, and had headed out on its ion drive until it was safely clear of the warping influence of planetary after His Effulgence's entourage arrived." the distorter drive had "Show him!" he ordered peremptorily. been activated, for the first time in Earth's history, and, for the The men of Earth had decided that it should work in theory. They had built the drive—a small machine, planet. To do so, said their theory, would usually—seven point three four times out of 10—destroy the His Effulgence beckoned to the thousands of miles around, in a ravening burst of raw energy. So the drive had been used for ship, and everything in space for Earth to be its twin sister. They had headed for that planet confidently and unsuspectingly, using the ion drive. , and had then tried to herd it away from the the Earthmen had acted distorter drive, and they had beaten the odds. On the distorter drive, they had returned to Earth as swiftly as they had departed. Earth had immediately prepared for war to His Effulgence and to Crownwall during the trip, without against her unknown enemy. interrupting the smooth progress bloody-minded Earthlings must which he had concealed his small transportation machine. The machine, for spatial mobility, was itself and the ships and those of my own race who manned them. We had tried to contact you, but equipped with the heavy and grossly inefficient anti-gravity field generator all who live on that planet. You could also have wrecked the planet just a routine quarantine. With your total lack of information "Could we have done anything else that would have kept you from landing on Earth and taking us over?" asked Crownwall. "Would that have been so bad?" was out of the atmosphere, before reach his ship from the palace of and uncontrolled in the Galaxy. starting his enormous journey Government of Earth, making a full report on his trip to Vega. When he had finished, the President through time back to Earth. More treaty with a Vegan. They sound ungodly murderous to me. There are too many holes in that protection organized a not inconsiderable defense. Your drones blew up our unmanned ships as fast as we could send them down to your planet. And by the time we had organized properly for war against you, it was across the Galaxy to meet him, to just to quarantine you. When we had used your radio system to teach a few of you the Universal he felt sure that we were safe from you—after all, there was no way for you to get off the planet. Even if you could get down to the bottom of the ocean and tamper Earthling," said His Effulgence. creatures that rule the Galaxy—are usurpers. They have no rights to their position of power. Our race that he couldn't face alone. for revenge. And now that you have entered space, that opportunity is at hand." "War in space is almost an impossibility," said the aged ruler. "We can destroy planets, of course, but with few exceptions, we cannot Each race settles on the planets that best suit it. Each of those planets is quite capable of defending itself from raids, or even large-scale assaults that would result in its capture and subjugation—just as your little Earth can defend itself. "Naturally, each is vulnerable to economic blockade—trade provides a small but vital portion of the goods each planet uses. All that a

<question>:
Why did the Viceroy blockade the Earth if he wanted an Earthling to come and meet with him?

<options>:
A The blockade was a test to see if Earthlings were smart enough to help the Vegans defeat the Sundans.
B The blockade is there to protect Earth from the Sundans.
C The blockade is there to quarantine the Earth. Earthlings may have diseases that could infect the other races.
D The blockade is there to keep people from leaving the Earth.

<answer>:

A