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

<passage>:
Sheer efficiency and good management can make a monopoly grow into being. And once it grows, someone with a tyrant mind is going to try to use it as a weapon if he can— [Transcriber's Note: This etext was produced from "That all, chief? Gonna quit now?" Brian Hanson looked disgustedly at Pete Brent, his lanky assistant. That was the first sign of animation he had displayed all day. "I am, but you're not," Hanson told him grimly. "Get your notes still on the vitamin research they had been conducting, he barely heard the remarks that followed him. of revolution among the disgruntled older families. apartment. This walk was part of a regular routine of physical exercise in precisely seven minutes, four and four-fifths seconds. He undressed and climbed into the tub, relaxing luxuriously in the exhilaration of irradiated water. He let all the problems of his work drift away, his mind was a peaceful meet astern. He paddled wetly across the floor sounding like a flock of regular routine. "Hello." The voice matched the calm alertness of a pair of deep-blue Now he got it. This was probably the young fool's idea of a joke. He'd soon fix that. "All right, joke's over, you can beat it now." "Joke? I don't see anything funny, unless it's you and that suggestive towel. You should either abandon it or get one that goes all the way round." austerely around him. "Well, now what?" she asked and looked at him questioningly. "Well, what do you think?" he burst out angrily. "I'm going to finish struggling heroically to refrain from laughing and that didn't help his dignity any. He strode into the bathroom, slammed the door and climbed back into the bath. force." "Get out of here!" he yelled and the door shut abruptly on a rippling satisfaction of the unending extra work that was going to occur around the laboratory from now on. He sank back into the soothing liquid embrace of the bath and deliberately set his mind loose to wander in complete relaxation. A hammering thunder burst on the outer door. He sat up with a groan. "Say! What the—" "Rebel? You're crazy! That was just ... Pete said ... rebel? Did you say rebel?" "Yeah, I said rebel, an' where is she?" pass the word along." Brian retired to his cell bunk and clutched his aching head in frustrated fury. For the nineteenth time Brian Hanson strode to the door of his cell and "Hello, pantless!" a voice breathed. "Guards are coming," a voice warned. "This way," he snarled and took the lead. He knew the ground plan of "Oh, you don't have to whisper, we're safe enough here. This is one of level tunnel. "What do we do? Hide here?" rebels crowded into it and they went rumbling swiftly down the echoing passage. The lights of the car showed the old working, rotten and twisting, tortuous course for half an hour, switching from one tunnel to another repeatedly until he had lost all conception of direction. going. The tunnel emerged in a huge cavern that gloomed darkly away in every "You're crazy, you can't get through there." "Oh, yeah? Just watch this." The ship thundered to life beneath them "We're going to crash! That gap isn't wide enough!" into some semblance of order. "That's some flying," he said as soon as he could speak. almost as soon as we can walk." set in grim lines as she pulled the ship up in a screaming climb. Brian got up off the floor. "You don't have to get excited like that," he complained. "They weren't "Authority doesn't make much difference to them," Crystal snapped bitterly. "They've been killing people all over the planet. What do you think this revolution is about?" "You must be mistak—" He slumped to the floor as Crystal threw the astern. "I guess that was a mistake!" Crystal yelled as she fought the controls. saw the crew battling their controls in startled terror. The ship slipped frantically away and fell into a spin. "That's them," Crystal said with satisfaction. "How are the others doing?" them. It was over in a few moments. The dead rebels drifted down into the mist-shrouded depths of the valley. "The dirty, murdering rats!" Brian's voice ripped out in a fury of outrage. "They didn't have a chance!" "Don't get excited," Crystal told him in a dead, flat voice. "That's just normal practice. If you'd stuck your nose out of your laboratory once in a while, you'd have heard of these things." through the fuselage. "They're after us now!" hung on nothing, then the ship fell over on its back and they screamed down in a terminal velocity dive, heading for the safety of the lower valley mists. The heavier police ship, with its higher wing-loading, ship out of its dive. " Phew! flickered closer and closer to the danger point. They tore loose from the clinging fog as it swung firmly to "Empty." The drive sputtered and coughed and died. "That's figuring it nice and close," Crystal said in satisfaction. "We can glide in from here." through the foliage—there was no crash. They burst through into a huge, brilliantly lighted cavern and settled to a perfect landing. Men thundered to life, streaked across the floor and burst out through the opening Crystal's ship had left. "He hasn't got a chance! We'll be spotted for sure, now." crescendoing roar of ships in a dive followed by the terrific crash of an explosion. "How come?" "Well, what do we do now? Just stand here? It looks like everybody's leaving." "We might as well just wait," Crystal said hopelessly. "It won't do us a dead silence. A score or more followed them without any attempt at Startled screams of agony burst from the crowded group of police as they were caught in the annihilating cross fire of roaring flame. They crisped and twisted, cooked to scorched horrors before they "Snap out of it," he barked. "That's no worse than shooting helpless men in parachutes. We can't go, yet we're not finished here." "Oh, let them shoot us! I can't go through that again!" mixture down till the exhaust was a lambent, shuddering stutter, verging on extinction. He dashed to the other ship and repeated the adjusted to critical fineness. The beat of the stuttering exhaust seemed to catch up to the other and built to an aching pulsation. In a moment the whole mass of air in the cavern hit the frequency with a subtle, intangible thunder of vibration. the line of the exhaust flames. The pulsating thunder in the cavern slope, the whole jungle muttered and groaned and came to life as it joined the roaring rush of the slide. They were tumbled irresistibly downward, riding the edge of the slide for terrifying minutes till it stilled and left them bruised and shaken in a tangle of torn vegetation. they attempted to land, stuck up grotesquely out of the foot of the slide. The dust was settling away. A flock of brilliant blue, gliding lizards barking in raucous terror, fled down the valley. Then they were gone and the primeval silence settled back into place. Brian and Crystal struggled painfully to solid ground. Crystal gazed with a feeling of awe at the devastated mountainside. "How did you do it?" "It's a matter of harmonics," Brian explained. "If you hit the right vibratory combination, you can shake anything down. But now that we've made a mess of the old homestead, what do we do?"

<question>:
How would you describe the changes in tone through the passage?

<options>:
A From detached to intense
B From excited to calm
C From scary to tranquil
D From calm to depressing

<answer>:

A