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

<passage>:
As the vastly advanced guardians of mankind, the Belphins knew how to make a lesson stick—but whom? still others painting pictures. Those who were without creative talent or the inclination to indulge it would be relaxing their well-kept golden bodies in whatever surroundings they had chosen to spend this particular one of the perfect days that stretched in an unbroken line before every member of the human race from the cradle to the crematorium. Only the Belphins were much in evidence. Only the Belphins had duties to perform. Only the Belphins worked. Ludovick stretched his own well-kept golden body and rejoiced in the knowing that he was a man and not a Belphin. Immediately afterward, he was sorry for the heartless thought. Didn't the Belphins work only to serve humanity? How ungrateful, then, it was to gloat over them! Besides, he comforted himself, probably, if the truth were known, the Belphins liked to work. He hailed a passing Belphin for assurance on this point. Courteous, like all members of his species, the creature leaped from the street and listened attentively to the young man's question. "We Belphins have but one like and one dislike," he replied. "We like what is right and we dislike what is wrong." "But how can you tell what is right and what is wrong?" Ludovick persisted. "You must warn as many Belphins as you can." "Then," she said dramatically, "you must approach The Belphin of Belphins himself." The Belphin. You're coming to A lifetime spent under their gentle guardianship had made Ludovick able to interpret the expression that flitted across this Belphin's frontispiece as a sad, sweet smile. the Belphins surrender their secrets to gratify the idle curiosity of a poet? "I must see The Belphin of Belphins. I must warn him against the Flockharts." "I don't trust you or your brothers. I must see The Belphin himself." Suddenly this particular Belphin lost his commanding manners. He began to wilt, insofar as so rigidly constructed a creature could go limp. "Please, we've done so much for you. Do this for us." "The Belphin of Belphins did things for us," Ludovick countered. "You are all only his followers. How do I know you are really following him? How do I know you haven't turned against him?" Behind his back, Corisande made a little filial face at Ludovick. Ludovick tried to make the old man see reason. "But I'm happy. And everybody is happy, except—except a few killjoys like you." "You fool...." it gasped. "Through your muddle-headed integrity ... you have destroyed not only me ... but Earth's future. I tried to make ... this planet a better place for humanity ... and this is my reward...." "But I don't understand!" Ludovick wept. " Why "They say," the uncle continued, impervious to Ludovick's unconcealed dislike for the subject, "that there's really only one Belphin, who lives in the Blue Tower—in a tank or something, because he can't breathe our atmosphere—and that the others are a sort of robot he sends out to do his work for him." The Belphin of Belphins died in Ludovick's arms. He was the last of his race, so far as Earth was concerned, for no more came. If, as they had said themselves, some outside power had sent them to take care of the human race, then that power had given up the race as a bad job. If they were merely exploiting Earth, as the malcontents had kept suggesting, apparently it had proven too dangerous or too costly a venture. Shortly after The Belphin's demise, the Flockharts arrived en masse. "We won't need your secret weapons now," Ludovick told them dully. "The Belphin of Belphins is dead." Corisande gave one of the rippling laughs he was to grow to hate so much. "Darling, "Even if The Belphin is a single entity," Ludovick went on, "that doesn't necessarily make him less benevolent——" He was again interrupted by the grandfather. "I won't listen to any more of this twaddle. Benevolent, bah! He or she or it or them is or are just plain exploiting us! Taking our mineral resources away—I've seen 'em loading ore on the spaceships—and——" "—and exchanging it for other resources from the stars," Ludovick said tightly, "without which we could not have the perfectly balanced society we have today. Without which we would be, technologically, back in the dark ages from which they rescued us." "It's not the stuff they bring in from outside that runs this technology," the uncle said. "It's some power they've got that we can't seem to figure out. Though Lord knows we've tried," he added musingly. "Of course they have their own source of power," Ludovick informed them, smiling to himself, for his old Belphin teacher had taken great care to instill a sense of humor into him. "A Belphin was explaining that to me only today." "See?" old Osmond remarked with satisfaction. "The kid's brain-washed. I told you so." "Nonsense, my boy "He said the Belphins rule through the power of love." they'll adore you. You'll be a hero!" Events proved him right. Even those people who had lived in apparent content under the Belphins, accepting what they were given and seemingly enjoying their carefree lives, now declared themselves to have been suffering in silent resentment all along. They hurled flowers and adulatory speeches at Ludovick and composed extremely flattering songs about him. on the other hand, could he stand idly by and let those neighbors attempt to destroy the social order? Deciding that the greater good was the more important—and that, moreover, it was the only way of taking Corisande away from all this—he went in search of a Belphin. That is, he waited until one glided past and called to him to leave the walk. The Belphin appeared to think for a minute. Then he gave off a smile. "Oh, them," he said. "We know. They are harmless." "Quite. And failed. For we are protected from hostile forces, as you were told earlier, by the power of love." Ludovick knew, of course, that the Belphin used the word metaphorically, that the Tower was protected by a series of highly efficient barriers of force to repel attackers—barriers which, he realized now, from the sad fate of Mieczyslaw and George, were potentially lethal. However, he did not blame the Belphin for being so cagy about his race's source of power, not with people like the Flockharts running about subverting and whatnot. "You certainly do have a wonderful intercommunication system," he murmured. "Everything about us is wonderful," the Belphin said noncommittally. "That's why we're so good to you people. Be happy!" And he was off. But Ludovick could not be happy. He wasn't precisely sad yet, but he was thoughtful. Of course the Belphins knew better than he did, but still.... Perhaps they underestimated the seriousness of the Flockhart conspiracy. On the other hand, perhaps it was he who was taking the Flockharts too seriously. Maybe he should investigate further before doing anything rash. Later that night, he slipped over to the Flockhart villa and nosed about in the courtyard until he found the window behind which the family was conspiring. He peered through a chink in the curtains, so he could both see and hear. "You suggest that we try to turn the power of love against the Belphins?" the uncle asked ironically.

<question>:
According to the story, is the Belphin good or evil?

<options>:
A He is good because he knows right and wrong
B Everyone has different opinions
C He is evil because he is controlling humans
D He is good because he is helping humans

<answer>:

B