One evening , it was raining and the wind was blowing hard . An old couple came to a small hotel and wanted to stay there for the night . A young man welcomed them warmly , but said "I'm sorry ! Our rooms here are all full and the hotels nearby are all full too, for there will be an important meeting held here tomorrow ." Hearing the young man's words , the old couple felt very disappointed , and turned around to leave . Just as they were leaving , the young man came up to them and stopped them :"Madam and sir ,if you don't mind , you can sleep in my bedroom for a night ." The next morning ,the old couple took out lots of money to give it to the young man ,but he refused to take it . "No! You needn't pay me any money , for I only lend my room to you." said the young man with a smile on his face. "You're great, young man! It's very kind of you .Maybe one day , I'll build a hotel for you ." said the old man. With these words , the old couple left . The young man only laughed and went on working . Several years later , the young man got a letter from the old couple , inviting him to go to Manhattan  . The young man met the old couple in front of a five-star hotel . "Do you still remember what I said to you several years ago ? Look ! This is the hotel that I built for you !" said the old man . Soon, the young man became the manager of the hotel. The young man only laughed because  _  .
he knew the old couple were poor the old man made a joke the couple thought too much of it he didn't like the gift