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 sprawling automatic brain's silver gauges and plastic toggles as proudly as if he had just personally gave birth to it. "This will need investigate this accident. The circumstances obviously are such that no false claim could be filed. Of course, the brain will make Investigate the Ozark village of Granite City. "It's too general. What does the nickel-brained machine mean by Before I headed for the hills, or the Ozark Mountains, I walked a few hundred feet down the hall and into the manual record files. The brain abstracted from empirical data but before I planed out to Granite City that concerned business was that the whole village of Granite City must granite from Granite City was being put into use all over the planet of all proportion. Furthermore, the work at the quarry could hardly explain the excessive for any kind of automobile accident from Granite City. prove is either right or wrong. Tentatively, I decided that for generations the citizens of Granite City had been in an organized conspiracy to defraud After so many profitable decades, Granite City wasn't going to take Despite headwinds we managed Mach 1.6 most of the way. My particular stewardess was a blonde, majoring in Video Psychotherapy in her night courses. I didn't have much time to get acquainted or more than hear copter to Granite City. Something about downdrafts in the mountains. Rolls. That was about the only brand of car that fit me. I hadn't been able to get my legs into any other foreign car since I was fifteen, and I have steadfastly refused to enter an American model since they all sold out their birthrights as passenger cars and went over to the tractor-trailer combinations they used only for cargo trucks when I was a boy. Dragging around thirty feet of car is sheer nonsense, even for painted frame buildings that was Granite City. They looked like a sports shirt. That was Granite Mountain in the near foreground. But I I wasn't too sure about that. Most of these guys who are on the hobo their initials belonged to some cult or other. I try to be as tolerant as I can, and some of my best friends are thugs, but I don't want to drive with them down lonely mountain roads. "Okay. It shouldn't be much of a walk in Granite City." like people to run automobiles on the streets of Granite City." the worse construction job I had seen in my life. It looked as mistake and put salt into it instead of sugar. Granite City than anywhere else in the country, per capita." "Yes, I understood you didn't like cars on your streets. At least not "That doesn't have anything to do with it. Nobody in Granite City owns "Showers," Thompson said. "With nonskid mats and handrails." I couldn't see any in the way they sliced the granite out of the The low, level snarl had come from a burly character in a syn-leather "What do you mean by that!" Kelvin demanded savagely. granite. Granite City exports some of the finest grade of the stone in "What's too bad?" "That you chose the wrong way so often," I said. "If this quarry has anything to do with defrauding Manhattan-Universal, Behind me were three restaurant tables and one solitary red-upholstered booth. Two men somewhere between forty and sixty sat at the nearest table playing twenty-one. "Hello, Professor," the fat man said. "What can we do for you?" "Positive. Ten cents, Professor." The man called "the professor" came over and sat down two stools away, More and more, I was coming to believe that Granite City wasn't a job society is criminal, distorted, you can't isolate the flaw. The whole village was meat for a sociologist let him figure out why otherwise decent citizens felt secure in conspiracy to defraud an honored corporation. I had merely established to my intuitive satisfaction that the job was not in my field. evidently thought him harmless enough to feed. The acne-faced kid behind the counter stared at me. I looked over and the old professor turned on his stool, his face pale and his eyes sad they refuse to trust to leave this place. They think they can't undesirable character he's under no obligation to give me telephone "Unfriendly of them," I said conservatively. "But how can they stop you He's been the only one in or out of Granite City for five months." granite itself? How do they ship it out?" "It's an artificial demand product, like diamonds," Professor Parnell and I've gotten even older since I came to Granite City." me the big query: Why are the good people of Granite City doing this to subhuman !" "I admit I have met likelier groups of human beings in my time." "No, understand me. These people are literally subhuman—they are inferior to other human beings." "Look, I know the Klan is a growing organization but I can't go along with you." "Madison, understand me, I insist. Ethnologically speaking, it is well known that certain tribes suffer certain deficiencies due to diet, climate, et cetera. Some can't run, sing, use mathematics. The people of Granite City have the most unusual deficency on record, I admit. Their psionic senses have been impaired. They are completely devoid of any use of telepathy, precognition, telekinesis." "Because they aren't supermen, that doesn't mean that they are submen," I protested. "I don't have any psionic abilities either." "But you do!" Parnell said earnestly. "Everybody has some psionics ability, but we don't realize it. We don't have the fabulous abilities of a few recorded cases of supermen, but we have some, a trace. Granite City citizens have no psionic ability whatsoever, not even the little that you and I and the rest of the world have!" "You said you were Duke University, didn't you?" I mused. "Maybe you know what you are talking about I've never been sure. But these people can't suffer very much from their lack of what you call psi ability." "I tell you they do," he said hoarsely. "We never realize it but we all have some power of precognition. If we didn't, we would have a hundred accidents a day—just as these people do . They can't foresee the flare a little higher and burn their fingers. There are other things, as well. You'll find it is almost impossible to carry on a lengthy conversation with any of them—they have no telepathic ability, no matter how slight, to see through the semantic barrier. None of them can play ball. They don't have the unconscious psionic ability to influence the ball in flight. All of us can do that, even if the case of a 'Poltergeist' who can lift objects is rare." won't go out and tell the rest of the world that they are submen?" "They don't want the world to know why they are psionically subnormal," he said crisply. "It's the granite why myself. I'm not a physicist or a biologist. But for some reason the heavy concentration and particular pattern of the radioactive radiation in its matrix is responsible for both inhibiting the genes that transmit psi powers from generation to generation and affecting those abilities in the present generation. A kind of psionic sterility." "How do you know this?" "We haven't the time for all that. But think about it. What else it be? It's that granite that they are shipping all over the world, spreading the contamination. I want to stop that contamination. To the people of Granite City that means ruining their only industry, putting them all out of work. They are used to this psionic sterility they don't see anything so bad about it. Besides, like everybody else, they have some doubts that there really are such things as telepathy and the rest to be affected."

<question>:
Why did the Professor call the people of Granite City "subhuman"?

<options>:
A He was exaggerating out of frustration with his inability to leave the city.
B He harbored racist sentiments.
C He was a member of the Ku Klux Klan.
D Their psionic deficiency rendered them incapable of essential human logic and reasoning.

<answer>:

D