A boy who was cleaning shoes in the street said to a young man, “Let me clean your shoes.” The young man said, “No, thank you.” “You may pay(支付) me only one dollar for them.” Said the boy. But the young man refused(拒绝) again.
And then the boy told the young man that he would clean his shoes for nothing. The young man            agreed to his, and soon one of his shoes became as clean as a new one. The man gave the other shoe to the boy, but the boy refused to clean it because he wanted the man to pay two dollars for his work. The young man refused to pay anything and went away.
But the dirty shoe looked so bad that he couldn’t walk away. He had to turn back and gave the boy two dollars. In a very short time the other shoe became clean.
At first the young man refused to let the boy clean his shoes, because        

A．he was very busy	B．he didn’t want to pay
C．he didn’t have enough money	D．he had cleaned his shoes

The young man agreed to let the boy clean his shoes, because the boy said he would ask for         

A．one dollar

B．two dollars

C．four dollars

D．nothing

The boy refused to clean the other shoe because         

A．it was very dirty	B．it was difficult to clean
C．the young man paid only one dollar	D．he wanted the young man to pay him

According to the passage, we know the boy        .
He is very foolish.  B. He is very selfish.   C. He is very clever.   D. He is very sad.