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

<passage>:
My partner was a fellow named Henry. He had an electronic surplus hardware business, but business wasn't good and he was looking for a little extra cash on the side. It turns out that the other little wholesalers in the loft building where he has his business are all card players, and no pikers, either. So Henry spread the word that he was available for a gin game—any time at all, but he would only play in his own place—he was expecting an important phone call and he I was supposed to be his stock clerk. While Henry and the other fellow And every time I got a look at his hand, I pushed the little button on the transmitter in my pocket. Every push on the button was a shock on Henry's leg. One for spades, two for hearts, three for diamonds, four for clubs. three for a queen, and so on down to the ten. A long and a short for nine, a long and two shorts for an eight ... it took a little memorizing, but it was worth it. Henry knew every card the other man held every time. And I got fifty per cent. So I called him out into the hall. "Skippy," I said—that's what we Express himself? He wouldn't played for big stakes ... and, nodding toward the kid and me, that he didn't like an audience. Henry looked at us miserably. But what was he going to do? If he didn't go along, the word could spread that maybe there was something wrong going on. He had to play. "Take the day off, you two," he said, but he Henry a wink and a nod toward the window. Then I took Skippy by the elbow and steered him out of there. Down in the street I said, fast: "You want to earn your pay? You have Because we still had a chance. With the field glasses and Skippy's we had a chance. Provided Henry had been able to maneuver Chapo so his got into the room and I laid it out for Skippy. "You aim those field players, didn't know the score but if he was giving the cards to me right, I was getting them out to Henry. I felt pretty good. I even began to feel kindly toward the kid. At my age, bifocals are standard equipment, but to judge from Skippy's fast, After about an hour, Skippy put down the glasses and broke the news: the game was over. We took our time getting back to Henry's place, so Chapo would have time to clear out. Henry greeted us with eight fingers in the air. Eight hundred? But before I could ask him, he was already talking: "Eight big ones! Eight thousand bucks! And how you did it, I'll never know!" Well, eight thousand was good news, no doubt of that. I said, "That's the old system, Henry. But we couldn't have done it if you hadn't window. I looked too, and then I saw what he was puzzled about. It was pretty obvious that Henry had missed my signal. He and the fish had played by the window, all right. When I turned around to look for Skippy, to ask him some questions, he I beat up and down every block in the neighborhood until I spotted him opened his mouth to say hello. I shook my head, but Skippy said, He couldn't quit—not until I found out how he read Chapo's cards through a drawn shade. He said drearily, "You've all got me marked lousy, haven't you? Don't kid me about Henry—I know. I'm not so sure about you, but it wouldn't surprise me." "What are you talking about?" "I can hear every word that's on Henry's mind," he said somberly. "You, no. Some people I can hear, some I can't you're one I can't." "All my life," said Skippy, "I've been hearing the voices. It doesn't could hear every thought that went through Chapo's mind, clear across the street. Henry too. That's how I know." He hesitated, looking at me. "You think Henry took eight thousand off Chapo, don't you? It was ten." I said, "Prove it." The kid finished his coffee. "Well," he said, "you want to know what the counterman's got on his mind?" He leaned over and whispered to me. I yelled, "That's a lousy thing to say!" Everybody was looking at us. He said softly, "You see what it's like? I don't want to hear all this stuff! You think the counterman's got a bad mind, you ought to listen in on Henry's." He looked along the stools. "See that fat little woman down at the end? She's going to order He hadn't even finished talking when the woman was calling the counterman, and she got another cheese Danish. I thought it over. What he said about Henry holding out on me made it real serious. I had to have more proof. But I didn't like Skippy's idea of proof. He offered to call off what everybody in the beanery was going to do next, barring three or four he said were silent, like me. That wasn't good enough. "Come along with and I knew his roulette wheel was gaffed. I walked right up to the The wheel spun, but that didn't stop the betting. Jake's hungry. In "Black," Skippy said. When Skippy said black, I put the fifty on red. Black won it. lot to learn. Jake's is no fair game. This was only a dry run." Then I got rid of him, because I had something to do. Henry came across. He even looked embarrassed. "I figured," he said, "uh, I figured that the expenses—" "Save it," I told him. "All I want is my split." a chance! It was going to be Skippy and me, all the way. Not only everything. Down at the track he could follow the smart-money guys And think of the fringe benefits! With Skippy giving the women a I could understand a lot about Skippy now—why he didn't like most over most of the human race. He didn't know what I was thinking. And then, take away the voices in his head, and Skippy didn't have much left. He wasn't very smart. If he had half as much in the way of brains as he did in the way of private radar, he would have figured all these We were all set to make a big score together, so I went back to his rooming house where I'd told him to wait, to get going on the big time. However, Henry had more brains than Skippy. I hadn't told Henry who tipped me off, but it didn't take him long to work out. After all, I had told him I was going out to look for Skippy, and I came right back and called him for holding out. No, it didn't take much brains. All he had to do was come around to Skippy's place So when I walked in the door, Skippy was there, but he was out cold, help a fine Swiss watch by pounding it on an anvil. Skippy could walk and talk all right, but something was missing. "The voices!" he yelled, sitting up on the edge of the bed. I got a quick attack of cold fear. "Skippy! What's the matter? Don't you hear them any more?" Like I say, I'm a genius. Skippy wouldn't lie to me he's not smart enough. If he says he hears voices, he hears voices. Being a genius, my theory is that when Henry worked Skippy over, he jarred his tuning strips, or whatever it is, so now Skippy's receiving on another frequency. Make sense? I'm positive about it. He sticks to the same story, telling me about what he's hearing inside his head, and he's too stupid to make it all up. There are some parts of it I don't have all figured out yet, but I'll because I have to get Skippy back in business. old neighborhood, but I haven't set up another partner for taking the card players. That seems like pretty small stuff now. And I don't talk to Henry when I see him. And I never go in the beanery when that

<question>:
How did Henry figure out that Skippy tipped the protagonist off?

<options>:
A Henry had been listening to the conversation
B The protagonist knew that Henry hid money from
C Skippy told Henry that he had done so
D The protagonist told Henry so

<answer>:

B