[单选题]When the French Institute in Haiti （海地）asked me to speak on a subject of my own choice, I picked heroism. It's a subject I know well. I've read many books about it.I spoke of some well-known heroes. I suggested that I was something of a hero myself. Then I told how the hero, in the face of danger, discovers all the great. lasting values of life.When I left the platform, a gentleman came to me. "Great lecture," he said. I'm Doctor Bonbon. I've been asked to make your stay here as pleasant as possible. Would you like to go hunting sharks with me? You seem to enjoy facing danger."I accepted gladly. I saw myself struggling with a huge fish on my rod...I was to speak again the next afternoon. So we agreed to start early in the morning.“By the way," the doctor said as we set out, “you should try out your coucteau." “My... what?"“Your snorkel （潜水呼吸管）.You need to breathe. I'll show you how to work the underwater gun too. What's the matter? Something wrong?"I had to sit down. I tried to tell myself it wasn't so. But there was no doubt about it. I wasn't to fish with a rod. I was to go right down into the water. I opened my mouth to protest...“You know,” the doctor said, "I can't tell you how much we all enjoyed your lecture on courage."I said nothing. There are times when you have to protect your means of earning a living. I was known as a good speaker. If I had to be eaten by sharks to keep my reputation, I was ready. I put on my mask.“Now put on the lead belt. It will get you down there instantly,M the doctor said. “They'll go down with you. " He pointed to the four big men on board.Bodyguards, I thought with relief.“They're the beaters （轰赶猎物的人）,” the doctor said. “They'll go ahead and drive the sharks toward you. Then all you have to do is shoot. ” I didn t have the courage to object. They helped me over the side.At the bottom the first thing I saw was a big fish. I screamed.I can't quite remember what followed. All I know is that, contrary to what I had said in my lecture, in the face of danger the hero does not discover the great values of life. At last I opened my eyes again. The big fish was gone.I tried to return to the surface. Then I saw a huge form above my head. I seized my gun. I closed my eyes and pressed the trigger.The gun was torn from me.In seconds I was at the surface. Luckily, the boat was near. I was on board in an instant. "Where s your gun?” asked the doctor.I explained that I had hit a shark. The beast had torn the weapon from my hands.The four big men were climbing back into the boat now. One of them had my gun. He spoke to the doctor in his native language.“It seems," the doctor said to me, "that you shot at the hull of the boat."He was trying to suggest that I had mistaken the boat passing over my head for a shark. The very idea!When I stepped to the platform that afternoon, Doctor Bonbon was sitting in the front row. But I didn't let his mocking stare disturb me. I was determined to rise once more to the level of my subject."Ladies and gentlemen," I began, "when the hero finds himself facing danger, the first thing he discovers..."When he was told that he was to go dowm into the water,the writer had to sit down probably because _______. A he could not control his shaking legs B he wanted to have a better look at the water C he wanted to get ready for the underwater adventure D he could not help asking Doctor Bonbon some questions