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

<passage>:
his eyebrows went up, and he made a beeline for Doc. Sandra wondered if The official laid a hand on Doc's shoulder. "Sir!" he said agitatedly. Not that there weren't enough humans around, it was the interest that was in doubt. The large hall was crammed with energetic dark-suited men of whom a disproportionately large number were bald, wore glasses, Sandra as a particularly maddening circumstance. Haupturnier or an intercollegiate won. It'll over its head be playing." Sandra's chief difficulty was that she knew absolutely nothing about looked down apprehensively at the person who had read her thoughts. It was a small sprightly elderly man who looked like a somewhat thinned down Peter Lorre—there was that same impression of the happy making a silvery nap. His pince-nez had quite thick lenses. But in sharp contrast to the somberly clad men around them, he was wearing a pearl-gray suit of almost exactly the same shade as Sandra's—a "Okay, lead on," Sandra said. "You're the doctor." "Then the name is yours as long as you want it—Doc." Meanwhile the happy little man had edged them into the first of a small cluster of tables, where a dark-suited jabbering trio was just rising. He snapped his fingers and hissed through his teeth. A white-aproned waiter materialized. "That'd go fine." Sandra leaned back. "Confidentially, Doc, I was Sandra briefly told him her story and her predicament. By the time they were served, Doc had absorbed the one and assessed the other. "You have one great advantage," he told her. "You know nothing understandably for your readers." He swallowed half his demitasse and smacked his lips. "As for the Machine—you know, I suppose, that it is not a humanoid metal robot, walking about clanking and squeaking like a late medieval knight in armor?" "Yes, Doc, but...." Sandra found difficulty in phrasing the question. Sandra grinned and nodded. Doc's ability to interpret her mind was as basis of capturing enemy pieces, working toward checkmate, establishing a powerful central position and so on." "That sounds like the way a man would play a game," Sandra observed. is like a man. A rather peculiar and not exactly pleasant man. A man who always abides by sound principles, who is utterly incapable of flights of genius, but who never makes a mistake. You see, you are finding human interest already, even in the Machine." Sandra nodded. "Does a human chess player—a grandmaster, I mean—ever "Most assuredly he does! In crucial situations, say where there's a chance of winning at once by trapping the enemy king, he examines is probably programmed to recognize such situations and do something of the same sort, though we can't be sure from the information World only look a very few moves ahead and must rely on his judgment and experience and artistry. The equivalent of those in the Machine is the directions fed into it before it plays a game." "You mean the programming?" "Indeed yes! The programming is the crux of the problem of the at enemy pieces and to retreat its own whenever they were attacked. It had a personality like that of a certain kind of chess-playing dub—a dull-brained woodpusher afraid to take the slightest risk of losing by blunders they could have avoided by looking only one or two moves ahead. The Machine will make no such oversights. Once again, you see, you have the human factor, in this case working for the Machine." "Savilly, I have been looking allplace for you!" A stocky, bull-faced man with a great bristling shock of black, gray-flecked hair had halted abruptly by their table. He bent over Doc and began to whisper explosively in a guttural foreign tongue. Sandra looked with quickening interest at the console of the Machine—a Sandra tried to think of a being who always checked everything, but that the Machine will play like a great oaf—at least against me . While Sandra arranged for an interview with Jandorf after the day's playing session, Doc reordered his coffee. "One expects it of Jandorf," he explained to Sandra with a philosophic moves. When a player makes a move he presses a button that shuts his clock off and turns his opponent's on. If a player uses too much time, he loses as surely as if he were checkmated. Now since the Machine will almost certainly be programmed to take an equal amount of time it was typical Jandorf bravado to make a point of a blindfold challenge—just as if the Machine weren't playing blindfold itself. Or is Grabo vs. Machine "Cripes, Doc, they all sound like they were Russians," Sandra said after a bit. "Except this Willie Angler. Oh, he's the boy wonder, isn't he?" Doc nodded. "Not such a boy any longer, though. He's.... Well, speak of , though. I was swindled, Savvy. I was robbed." "Willie!" Doc said with some asperity. "Miss Grayling is a journalist. She would like to have a statement from you as to how you will play against the Machine." Doc and Sandra looked at each other and smiled. Doc's smile became tinged with sad understanding. "You must excuse "Correct. Their advertising department is interested in the prestige. They want to score a point over their great rival." "But if the Machine plays badly it will be a black eye for them," Doc gave a short scornful laugh. "Krakatower! Don't pay any attention to him . A senile has-been, it's a scandal he's been allowed to play Krakatower." "Take it easy, Doc. He sounds like he would make an interesting article? Can you point him out to me?" "You can tell him by his long white beard with coffee stains. I don't "And Grabo?" Sandra pressed, suppressing a smile at the intensity of Doc's animosity. Doc's eyes grew thoughtful. "About Bela Grabo (why are three out of He would not amplify his statement. Sandra studied the Scoreboard again. "This Simon Great who's down as programming the Machine. He's a famous physicist, I suppose?" Doc spoke his piece for Sandra. "That makes it very tough on you," Sandra put in. "The Machine isn't "You know, Doc," Sandra said, "I'm a dog to suggest this, but what if this whole thing were a big fake? What if Simon Great were really playing the Machine's moves? There would surely be some way for his electricians to rig—" Doc laughed happily—and so loudly that some people at the adjoining games with the Machine to assure himself that it operates legitimately and has grandmaster skill." famous chess-playing automaton of the 19th Century? That one too was supposed to work by machinery (cogs and gears, not electricity) but actually it had a man hidden inside it—your Edgar Poe exposed the fraud in a famous article. In better player than either of them ... yes, yes! Your Ambrose Bierce too wrote a story about a chess-playing robot of the clickety-clank-grr While Doc chattered happily on about chess-playing robots and chess He was older than she'd first assumed. She could see that now that she was listening to him less and looking at him more. Tired, too. Only his dark-circled eyes shone with unquenchable youth. A useful old guy, whoever he was. An hour ago she'd been sure she was going to muff this assignment completely and now she had it laid out cold. For the umpteenth time in her career Sandra shied away from the guilty thought that she wasn't a writer at all or even a reporter, she just used dime-a-dozen female attractiveness to rope a susceptible man (young, old, American, Russian) and pick his brain.... Doc was the only person still talking and people were again looking at Like morticians' assistants

<question>:
What role does Doc play for Sandra?

<options>:
A He plays a comedic role.
B He plays a condescending role.
C He plays an entertaining role.
D He plays an informative role.

<answer>:

D