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 a working balance in our Empire. We control it adequately, and we live in peace. "The Sundans, for example, Sunda. He ignored the snarling, the Empire that was rightfully ours away from us, through trickery, were unable to take over the Sectors we control. We are still powerful. And soon we will be all-powerful. In company with you Earthlings, that is." the unfamiliar planet. mass of eight-foot creatures, words, you think that we Earthmen stalemate. You've got the idea that, with our help, you can conquer planets without the necessity of destroying them, and thereby take over number one spot from can break up this two-million-year-old If they carried out the threats of friends," growled Ggaran. He subsided their present attitude, Earth would have to send Marshall to replace unconcern that he felt sure was entirely of the Universal Holy Empire of what do you want of us?" arrange something a little more trustworthy, I believe. On your 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 you have said, there are more planets that belong to you than there are human beings on Earth. But sure that you will behave yourselves. You will transfer to us, at once, a hundred of your planet-destroying bombs. That will be a sufficient supply to let us test some of them, to see that they are in will be able to use our own methods—which 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 destroy any planet you choose to land on. You would not get away from us. We can track you without any difficulty. "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 Earth. How does that sound to make very satisfactory allies. What why we cannot proceed with "It's customary to genuflect Earthling. I suppose we can expect customary among civilized peoples." exclamation of protest. "Oh, you that we don't travel in space useless—and very dangerous—knowledge." "So have we, up until the time you planted that bomb on us. Anyone who tried to work any changes 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 in his own past would be almost told you that Earthlings were unbelievably come, so I can tell you that although I am the leader of one of the mightiest peoples in the Galaxy, whereas there are scarcely six billions of you squatting on one minor planet, we still need each other. Together, there is nothing we can't do." us to take over the rule of the Galaxy from the Sunda—the so-called of one of the hundred Sectors of the Empire. I rule over a total of a hundred Satrapies these average and every Cluster has an average of a hundred inhabited solar systems. There are more inhabited planets in the Galaxy than there for your own safety?" asked own race. And yet I tell you that "I don't get it. Why?" upstart Earthlings are a strange "Frightening to the Sunda, especially. bombs and start making arrangements." "Excellent," said Ffallk. "I'd better escort you had to be stopped at once. There Earth out of hand, while it is still possible. "Your silly little planet was carefully examined at long range in a routine investigation just about fifty was even serious discussion of destroying similar racial strains of pulpy bipeds, shrill two-tone note, using both his lack of civilization. While these creatures could by no means be classed among the intelligent races, "Intelligence is very rare in the along at seven or eight kilometers an hour, carrying their contraption with absolute smoothness. Blasts "You Earthlings, in defiance of all expectation and all reason, have exploded into space. You have developed in an incredibly short space of time. But even that isn't and had headed out on its ion drive until it was safely clear of the warping influence of planetary masses. Then, after several impatient days of careful study and calculation, 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 ship, and everything in space for thousands of miles around, in a ravening burst of raw energy. of civilization. The men of Alpha Centauri. They had quickly located a dozen planets, and one that looked enough like Earth to be its twin sister. They had headed for that planet confidently and unsuspectingly, using the ion drive. from their destination, they had been shocked to find more than two score alien ships of space closing in on them—ships that were swifter and more maneuverable than their own. These ships had rapidly and competently englobed the "Oh, no. They are far too brutal, really an uncouth bunch. Why, do use an energy weapon to dispose of the victim in a case such as you just witnessed! They are really decision. Although far within the dangerous influence of a planetary mass, they had again activated the distorter drive, and they had beaten against her unknown enemy. bloody-minded Earthlings must danger." You knew that you could have destroyed not only yourself, but also all who live on that planet. You could also have wrecked the planet itself and the ships and those of equipped with the heavy and grossly inefficient anti-gravity field generator my own race who manned them. which he had concealed his small transportation machine. The machine, but it had the great advantage of being almost undetectable in use. It emitted no mass or radiation. just a routine quarantine. With and uncontrolled in the Galaxy. Once was enough for that." in view of the fact that we'll undoubtedly be it took us a little time to react. We located your planet quickly enough, blown into atoms if we don't. But from what you say, I'd rather be 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 obvious that we could not conquer you. We could only destroy you." just to quarantine you. Galactic tongue, and had managed to get what you call the 'planet-buster' down into the largest of your oceans, he figured we had done our job. Even if you could get down to the bottom of the ocean and tamper with the bomb, you would only succeed in setting it off, and that's what the Sunda had been in favor Crownwall. "Our enemies are all "We're all alone now." bowed. "The crustaceans on Sunda—the lobsterlike creatures that rule the Galaxy—are usurpers. They have no rights to their position of power. Our race that he couldn't face alone. primitive tribe, grubbing in the to reason, almost as well as we, The "War in space is almost an impossibility," said the aged ruler. "We can destroy planets, of course, but with few exceptions, we cannot conquer them. I rule a total of 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>:
Which is the best deccription of why the humans are feared by other alien races?

<options>:
A Their technology and ideas develop at a rapid pace
B They are known to wipe out alien races with their time travel technology
C They have superior strategies to get past any race's defense system
D They have control of large amounts of bombs that can be used to destroy planets

<answer>:

A