A shopkeeper sent his son to learn about the secret of happiness from the wisest man in the world. The boy walked a long way, and finally came upon the beautiful castle where the wise man lived. On entering the main room of the castle, the boy was quite surprised: tradesmen coming and going, people chatting in the corners, and a small orchestra playing soft music. The wise man talked with everyone, and the boy had to wait for two hours before it was his turn. The wise man listened carefully to the boy's explanation of why he had come, but told him that he didn't have time just then to explain the secret of happiness. He suggested that the boy look around the palace and return in two hours. "Meanwhile, I want to ask you to do something," said the wise man, handing the boy a teaspoon that held two drops of oil. "As you wander around, carry this spoon with you without allowing the oil to spill." The boy began to walk up and down stairs of the palace, keeping his eyes fixed on the spoon. After two hours, he returned to the wise man. "Well," asked the wise man, "Did you see the Persian tapestries in the hall? Did you see the garden that took the master gardener ten years to create?" The boy was embarrassed, and replied that he had observed nothing. His only concern had been not to spill the oil. "Then go back and observe the wonders of my world," said the wise man. The boy picked up the spoon and returned to his exploration of the palace. This time he observed all of the works of art on the ceilings and the walls. When he returned, he described in detail everything he had seen. "But where are the drops of oil?" asked the wise man. Looking down at the spoon he held, the boy saw that the oil was gone. "Well, there is only one piece of advice I can give you," said the wise man. "The secret of happiness is to see all the wonders of the world, and never to forget the drops of oil on the spoon." We can infer from the article that "the drops of the oil on the spoon" probably refer to  _  .
the beauty of one's nature the fortune a person possesses the responsibilities one has to take on the great opportunities in life
Question: A shopkeeper sent his son to learn about the secret of happiness from the wisest man in the world. The boy walked a long way, and finally came upon the beautiful castle where the wise man lived. On entering the main room of the castle, the boy was quite surprised: tradesmen coming and going, people chatting in the corners, and a small orchestra playing soft music. The wise man talked with everyone, and the boy had to wait for two hours before it was his turn. The wise man listened carefully to the boy's explanation of why he had come, but told him that he didn't have time just then to explain the secret of happiness. He suggested that the boy look around the palace and return in two hours. "Meanwhile, I want to ask you to do something," said the wise man, handing the boy a teaspoon that held two drops of oil. "As you wander around, carry this spoon with you without allowing the oil to spill." The boy began to walk up and down stairs of the palace, keeping his eyes fixed on the spoon. After two hours, he returned to the wise man. "Well," asked the wise man, "Did you see the Persian tapestries in the hall? Did you see the garden that took the master gardener ten years to create?" The boy was embarrassed, and replied that he had observed nothing. His only concern had been not to spill the oil. "Then go back and observe the wonders of my world," said the wise man. The boy picked up the spoon and returned to his exploration of the palace. This time he observed all of the works of art on the ceilings and the walls. When he returned, he described in detail everything he had seen. "But where are the drops of oil?" asked the wise man. Looking down at the spoon he held, the boy saw that the oil was gone. "Well, there is only one piece of advice I can give you," said the wise man. "The secret of happiness is to see all the wonders of the world, and never to forget the drops of oil on the spoon." We can infer from the article that "the drops of the oil on the spoon" probably refer to  _  .
A. the beauty of one's nature
B. the fortune a person possesses
C. the responsibilities one has to take on
D. the great opportunities in life
Answer: