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

<passage>:
THE RUMBLE AND THE ROAR BY STEPHEN BARTHOLOMEW The noise was too much for him. He wanted quiet—at any price. [Transcriber's Note: This etext was produced from Worlds of If Science Fiction, February 1957. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] When Joseph got to the office his ears were aching from the noise of the copter and from his earplugs. Lately, every little thing seemed to make him irritable. He supposed it was because his drafting department was behind schedule on the latest Defense contract. His ears were sore and his stomach writhed with dyspepsia, and his feet hurt. Walking through the clerical office usually made him feel better. The waved to a few of the more familiar employees and smiled, but of course you couldn't say hello with the continual racket. This morning, somehow, it didn't make him feel better. He supposed it Boom," the latest Top Hit. He hated that song. Of course the National Mental Health people said constant music had a huge window for awhile, watching the cars on the freeway and listening to the homogeneous rumble and scream of turbines. Something's wrong with me , he thought. I shouldn't be feeling this way. Nerves. Nerves. "Betty," he told her, "I want you to make an appointment with my therapist for me this afternoon. Tell him it's just a case of nerves, though." "Yes sir. Anything else?" Her voice, like every one's, was a high pitched screech trying to be heard above the noise. Joseph winced. "Anybody want to see me this morning?" "Well, Mr. Wills says he has the first model of his invention ready to show you." "Let him in whenever he's ready. Otherwise, if nothing important comes up, I want you to leave me alone." He spent about an hour on routine paperwork and then Bob Wills showed up so Joseph switched off his dictograph and let him in. "I'm afraid you'll have to make it brief, Bob," he grinned. "I've a whale of a lot of work to do, and I seem to be developing a splitting headache. Nerves, you know." "Sure, Mister Partch. I won't take a minute I just thought you'd like progress so far...." "Yes, yes, just go ahead. How does the thing work?" Bob smiled and set the grey steel chassis on Partch's desk, sat down in front of it, and began tracing the wiring for Joseph. It was an interesting problem, or at any rate should have been. It was one that had been harassing cities, industry, and particularly air-fields, for many years. Of course, every one wore earplugs—and that helped a little. And some firms had partially solved the problem technological civilization forced everyone to endure. The noise from a commercial rocket motor on the ground had been known to drive men mad, and sometimes kill them. There had never seemed to be any wholly satisfactory solution. we've got several possible answers in mind and we're working on all of them." He caressed the crackle-finish box fondly. "The basic gimmick works fine, though. Yesterday I took it down to a static test stand over in building 90 and had them turn on a pretty fair-sized steering rocket for one of the big moon-ships. Reduced the noise-level by about 25 per cent, it did. Of course, I still needed my plugs." Joseph nodded approvingly and stared vacantly into the maze of transistors and tubes. "I've built it to work on ordinary 60 cycle house current," Wills told him. "In case you should want to demonstrate it to anybody." it here in my office and I'll look it over later, hm?" "Okay, Mr. Partch." Partch had Betty send him in a light lunch and he sat behind his desk nibbling the tasteless stuff without much enthusiasm. He wondered if he was getting an ulcer. Yes, he decided, he was going to have to have a long talk with Dr. Coles that afternoon. Be a pleasure to get it all off his chest, his feeling of melancholia, his latent sense of doom. Be good just to talk about it. Oh, everything was getting to him these days. He was in a rut, that was it. A rut. fingers and thought about it. What would he do this evening after work, for instance? Why, he'd stuff his earplugs back in his inflamed ears and board the commuter's copter and ride for half an hour listening to the drumming of the rotors and the pleading of the various canned commercials played on the copter's speakers loud enough to be heard over the engine noise and through the plugs. And then when he got home, there would be the continuous yammer of his wife added to the Tri-Di set going full blast and the dull food from the automatic kitchen. And synthetic coffee and one stale cigaret. Perhaps a glass of brandy to steady his nerves if Dr. Coles approved. Partch brooded. The sense of foreboding had been submerged in the day's work, but it was still there. It was as if, any moment, a hydrogen bomb were going to be dropped down the chimney, and you had no way of knowing when. And what would there be to do after he had finished dinner that night? Why, the same things he had been doing every night for the past fifteen years. There would be Tri-Di first of all. The loud comedians, and the musical commercials, and the loud bands, and the commercials, and the loud songs.... And then, at last, it would be time to go to bed, and the murmur of the somnolearner orating him on the Theory of Groups all through the long night. And in the morning, he would be shocked into awareness with the clangor of the alarm clock and whatever disc jockey the clock radio happened to went screaming through the streets like wounded dragons. Sirens, bells. Police whistles. Almost, it was like trying to imagine what a negation of space And then he turned, and his eyes fell on Bob Wills' machine. It could said. Here in the office, the sound level was less than that of a rocket motor. And the machine worked on ordinary house current, Bob had said. Partch had an almost horrifying idea. Suppose.... But what would Dr. Coles say about this, Partch wondered. Oh, he had to get a grip on himself. This was silly, childish.... But looking down, he found that he had already plugged in the line cord. An almost erotic excitement began to shake Joseph's body. The sense of disaster had surged up anew, but he didn't recognize it yet. An absence of sound And then the dream came back to him, the nightmare of the night before that had precipitated, unknown to him, his mood of foreboding. It came back to him with stark realism and flooded him with unadorned fear. completely alone. And it was—quiet. Doctor Coles looked at the patient on the white cot sadly. "I've only seen a case like it once before in my entire career, Dr. Leeds." Leeds nodded. "It is rather rare. Look at him—total catatonia. He's curled into a perfect foetal position. Never be the same again, I'm afraid." "The shock must have been tremendous. An awful psychic blow, especially to a person as emotionally disturbed as Mr. Partch was." "Yes, that machine of Mr. Wills' is extremely dangerous. What amazes me is that it didn't kill Partch altogether. Good thing we got to him when we did." Dr. Coles rubbed his jaw. "Yes, you know it is incredible how much the human mind can sometimes take, actually. As you say, it's a wonder it didn't kill him." He shook his head. "Perfectly horrible. How could any modern human stand it? Two hours, he was alone with that machine. Imagine— two hours of total silence!"

<question>:
How many times was Bob’s machine tested?

<options>:
A Never before
B It had been in development for years, so many tests
C At least once before Mr. Partch plugged it in
D It had undergone weeks of testing

<answer>:

C