One fine afternoon, while walking, I remembered that I needed a pair of socks.  I turned into a sock shop that caught my eye, and a boy clerk who was about 17 came forward. "What can I do for you, sir?" There was a note of passion in his voice.  "Did you know that you have come into the finest place in the world to buy socks? Come with me," said the boy.  I followed him to the back of the shop, and he began to take down from the shelves box after box of socks. "I am going to buy only one pair!" "I know that," said he, "but I want you to see how beautiful these are. Aren't they wonderful?" I became far more interested in him than in the socks. I looked at him in surprise. "My friend," said I, "if you can keep this up, if this is not just the enthusiasm that comes from having a new job, if you can keep up this excitement day after day, in ten years you will be a good businessman."   My surprise at his pride and joy in his salesmanship will be easily understood by all who read this article.  In many shops the customer has to wait for someone to serve him. And when finally some shop assistant notices you, you are made to feel as if you were interrupting him. He displays no interest either in you or in the goods he is paid to sell. It's possible that every shop assistant who is now so bored began his career with hope and enthusiasm. I have observed this happen in the lives of so many men. I have come to the conclusion that the surest road to failure is to do things mechanically . The reason why the writer walked into the sock shop was that  _   .
he knew the boy well it was a big shop having the most beautiful socks the boy clerk was warm-hearted he happened to notice it
Question: One fine afternoon, while walking, I remembered that I needed a pair of socks.  I turned into a sock shop that caught my eye, and a boy clerk who was about 17 came forward. "What can I do for you, sir?" There was a note of passion in his voice.  "Did you know that you have come into the finest place in the world to buy socks? Come with me," said the boy.  I followed him to the back of the shop, and he began to take down from the shelves box after box of socks. "I am going to buy only one pair!" "I know that," said he, "but I want you to see how beautiful these are. Aren't they wonderful?" I became far more interested in him than in the socks. I looked at him in surprise. "My friend," said I, "if you can keep this up, if this is not just the enthusiasm that comes from having a new job, if you can keep up this excitement day after day, in ten years you will be a good businessman."   My surprise at his pride and joy in his salesmanship will be easily understood by all who read this article.  In many shops the customer has to wait for someone to serve him. And when finally some shop assistant notices you, you are made to feel as if you were interrupting him. He displays no interest either in you or in the goods he is paid to sell. It's possible that every shop assistant who is now so bored began his career with hope and enthusiasm. I have observed this happen in the lives of so many men. I have come to the conclusion that the surest road to failure is to do things mechanically . The reason why the writer walked into the sock shop was that  _   .
A. he knew the boy well
B. it was a big shop having the most beautiful socks
C. the boy clerk was warm-hearted
D. he happened to notice it
Answer: