It doesn't matter when or how much a person sleeps, but everyone needs some rest to stay alive.That's what all doctors thought, until they heard about Al Herpin.Al Herpin, it was said, never slept. Could this be true? The doctors decided to see this strange man themselves.  Al Herpin was 90 years old when the doctors came to his home in New Jersey. They thought for sure that he got some sleep of some kind.So they stayed with him and watched every movement he made. But they were surprised. Though they watched him hour after hour and day after day, they never saw Herpin sleeping.In fact, he did not even own a bed. He never needed one.  The only rest that Herpin sometimes got was sitting in a comfortable chair and reading newspapers.  The doctors were puzzled by this strange continuous sleeplessness.They asked him many questions, hoping to find an answer.They found only one answer that might explain his condition.Herpin remembered some talk about his mother having been injured several days before he was born.But that was all.Was this the real reason? No one could be sure.  Herpin died at the age of 94. One reason that might explain Herpin's sleeplessness was   _  .
his mother's injury before he was born that he had gradually got rid of the sleeping habit his magnificent physical condition that he hadn't got a bed
Question: It doesn't matter when or how much a person sleeps, but everyone needs some rest to stay alive.That's what all doctors thought, until they heard about Al Herpin.Al Herpin, it was said, never slept. Could this be true? The doctors decided to see this strange man themselves.  Al Herpin was 90 years old when the doctors came to his home in New Jersey. They thought for sure that he got some sleep of some kind.So they stayed with him and watched every movement he made. But they were surprised. Though they watched him hour after hour and day after day, they never saw Herpin sleeping.In fact, he did not even own a bed. He never needed one.  The only rest that Herpin sometimes got was sitting in a comfortable chair and reading newspapers.  The doctors were puzzled by this strange continuous sleeplessness.They asked him many questions, hoping to find an answer.They found only one answer that might explain his condition.Herpin remembered some talk about his mother having been injured several days before he was born.But that was all.Was this the real reason? No one could be sure.  Herpin died at the age of 94. One reason that might explain Herpin's sleeplessness was   _  .
A. his mother's injury before he was born
B. that he had gradually got rid of the sleeping habit
C. his magnificent physical condition
D. that he hadn't got a bed
Answer: