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 Man Who Was Six By F. L. WALLACE Illustrated by ASHMAN [Transcriber's Note: This etext was produced from Galaxy Science Fiction September 1954. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] There is nothing at all like having a sound mind in a sound body, but Dan Merrol had too much of one—and also too much of the other! just can't believe you're my husband." He felt his own yawn slip off his face. "What do you mean? What am I doing here then?" I should know, shouldn't I?" "Of course, but...." He did some verbal backstepping. "It was a bad accident. You've got to expect that I won't be quite the same at first." He sat up. " had to use whatever was handy." "I suppose so—but shouldn't they have tried to stick to the original "They told you that at the hospital." They hadn't—he'd read it on the chart. But he had been alone in the room and the name had to be his, and anyway he felt like Dan Merrol. "Your name is Erica." "They told you that too." She was wrong again, but it was probably wiser not to tell her how he He'd got up and read the chart and searched dizzily through the closet. Clothes were hanging there and he'd put them on and muttered her name to himself. He'd sat down to gain strength and after a while he'd walked out and no one had stopped him. It was night when he left the hospital and the next thing he remembered to convince her there. But he'd been frantic to get home. "It was quite a smashup," he said. "You'll have to expect some lapses." "I'm making allowances. But can't you tell me something about myself?" "What's that?" "At the moment, who knows? Anyway, I'm a well-known actor and a musician and a first-rate mathematician. I can't remember any equations thought of it, and it didn't seem right. She sighed and drew away. "That was a lucky guess on your age." Did that mean he wasn't right on anything else? From the expression "Did I do that?" he asked. "You did, though I'm sure you didn't mean to. I don't think you realized how strong you were. Dan was always too gentle—he must have some explanation for the added height. He glanced down at his legs. They were the same length from hip bone to the soles of his feet, but the proportions differed from one side to the other. His knees didn't match. Be-dum, be-dum, be-dumdum, but your knees don't match —the snatch of an ancient song floated through his head. they were patching him up, did they really think he needed black, red and brown hair? He wondered how a beagle felt. What were they, a bunch of humorists? Did they, for comic effect, piece together a body out of bits and scraps left over from a chopping block? It was himself he was looking at, otherwise he'd say the results were neither hideous nor horrible, but merely—well, what? Ludicrous and an involuntary clown, a physical buffoon that Mother Nature hadn't duplicated since Man began? He felt the stubble on his face with his left hand—he thought it generally, though not around the chest. It was difficult and in addition to his physique there were the memories he couldn't account for. Come to think of it, he must have been awfully busy to have so many careers in such a short time— and scrambled face, to the mismatched lumps and limbs and shapes that, stretching the term, currently formed his body. It was clear what he had to do. stuffed it in the toe. He looked critically at himself in the mirror. Dressed, his total effect was better than he had dared hope it would be. True, he did look He must have given some explanation as he'd stumbled through the door. What was it? "What's Wysocki's theorem?" she asked. Whose theorem?" "Wysocki's. I started to call the hospital and you wouldn't let me, because of the theorem. You said you'd explain it this morning." She coordination. She could have been terrified, might have resisted—but she hadn't. At that time, she must have half-believed he was Dan She was looking at him, waiting for that explanation. He shook his mind frantically and the words came out. "Self-therapy," he said and carry them through by himself, even though running a slight risk of physical complications." "That's new, isn't it?" she said. "I always thought they watched the patient carefully." It ought to be new—he'd just invented it. "You know how rapidly medical practices change," he said quickly. "Anyway, when they examined me last night, I was much stronger than they expected—so, It was a domestic miracle that amidst all the pressing and fitting, she'd somehow prepared breakfast and he hadn't noticed. It was a simple chore with the automatics, but to him it seemed a proof of her wifely skill. Not a thing, now that she asked. In fact, there wasn't much he did remember. There had been the chart at his bed-side, with one word scrawled on it— accident —and that was where he'd got the idea. There had been other marks too, but he hadn't been able to decipher them. He but he might have been tossed there—impact did strange things. Dan Merrol was a spaceship pilot and he hadn't included it among his skills. It was strange that she had believed him at all. But now that it was out in the open, he did remember some facts about spaceships. He felt he could manage a takeoff at this instant. But why hadn't he told her? Shock? Perhaps—but where had those other identities come from—lepidopterist, musician, actor, mathematician and wrestler? And where had he got memories of wives, slender and passionate, petite and wild, casual and complaisant, nagging and "They said they'd identified everyone, living or dead, and I supposed they had. After seeing you, I can believe they made any number of fell." Even if he was sure, he didn't know whether he could tell her—and he "Wysocki's theorem," he told her. "The patient has decided to walk." "Otherwise.... You're an intolerable funny man." He knew it—he could see himself in the mirror. He was something to Last night, on an impulse, he'd left the hospital and now he had to go back. polite expression became a grimace of barely suppressed laughter. Then laughter was swept away. What replaced it he couldn't say, but it It seemed wiser to Dan not to tell him everything. "It was stuffy identify me as the person who came out of regrowth—but does that mean I'm Dan Merrol? Could there be a mistake?" Crander eyed him clinically. "We don't ordinarily do this—but it is "Here is other evidence you may not have heard of. It's a recent development, within the last ten years, in fact. It still isn't The mass-cell radiographs did seem identical and Dr. Crander seemed certain. Taken altogether, the evidence was overwhelming. There had been no mistake—he was Dan Merrol, though it was not difficult to understand why Erica couldn't believe he was her husband. The other just didn't understand. "But the size—it doesn't match my arm!" "Doesn't This was discovered long ago, by someone I've forgotten. But there are other factors just as potent and far more complex." He scribbled meaningless symbols on the screen with his finger. "Take learned the essentials. He was Dan Merrol and there was nothing they Kaufman, musician—Breed Mannly, cowboy actor—George Elkins, lepidopterist—Duke DeCaesares, wrestler—and Ben Eisenberg, mathematician, went into the places I tapped."

<question>:
How was Dan able to explain Wysocki's theorem?

<options>:
A He did not explain it
B Dr. Crander told him
C One of his previous memories told him
D He made it up

<answer>:

D