One day, a poor man, who had only one piece of bread to eat, was walking past a restaurant. There was a large pot of soup on the table. The poor man held his bread over the soup, so the steam from the soup went into the bread, and gave it a good smell. Then he ate the bread. The restaurant owner was very angry at this, and he asked the man for money, in exchange for the steam from the soup. The poor man had no money, so the restaurant owner took him to Nasreddin, who was a judge at that time. Nasreddin thought about the case for a little while. Then he took some money from his pocket. He held the coins next to the restaurant owner's ear, and shook them, so that they made a dingling noise. "What was that?" asked the restaurant owner. "That was payment for you," answered Nasreddin. "What do you mean? That was just the sound of coins!" protested   the restaurant owner. "The sound of the coin is payment for the smell of the soup," answered Nasreddin. "Now go back to your restaurant." The writer's purpose in telling the story is mainly to   _  .
show the restaurant owner's greed describe the poor's unhappy life show Nasreddin's cleverness and humour prove the value of the sound of coins
Question: One day, a poor man, who had only one piece of bread to eat, was walking past a restaurant. There was a large pot of soup on the table. The poor man held his bread over the soup, so the steam from the soup went into the bread, and gave it a good smell. Then he ate the bread. The restaurant owner was very angry at this, and he asked the man for money, in exchange for the steam from the soup. The poor man had no money, so the restaurant owner took him to Nasreddin, who was a judge at that time. Nasreddin thought about the case for a little while. Then he took some money from his pocket. He held the coins next to the restaurant owner's ear, and shook them, so that they made a dingling noise. "What was that?" asked the restaurant owner. "That was payment for you," answered Nasreddin. "What do you mean? That was just the sound of coins!" protested   the restaurant owner. "The sound of the coin is payment for the smell of the soup," answered Nasreddin. "Now go back to your restaurant." The writer's purpose in telling the story is mainly to   _  .
A. show the restaurant owner's greed
B. describe the poor's unhappy life
C. show Nasreddin's cleverness and humour
D. prove the value of the sound of coins
Answer: