Read the following article and select the best answer. Article: Have you ever wanted to achieve something really amazing in life? Well, Greg Mortenson wanted to climb a mountain, but he ended up helping thousands of people to have a better life. Greg's story began with failure. In 1993, he set out to climb K2, the world's second highest mountain. But Greg never made it to the top. After five days, he stumbled into the village of Korphe in northern Pakistan, injured and hungry. The kind villagers there looked after him for several days. Greg saw that the villagers were very poor and hungry, and some of them were ill. Also, the village school didn't have a roof and the children wrote on the ground with sticks, Greg knew he wanted to do something to help. "I'll build you a school," he told the villagers. "I promise." Greg went back home to the USA to raise money for the school. He even lived in the car to save money! Finally he went back to Korphe and built the school. But _ was just the beginning of something bigger! Since then, Greg's organization has built around 80 schools and runs many others in Pakistan and other countries, too. Greg hasn't finished yet. He does many other things to help people in poor countries. He has got many prizes, but it's the smiles of the children he has helped that makes him happy! Greg has just written a best-selling book about his story called Three Cups of Tea. It's an interesting and exciting book which tells us what ordinary people can do with courage and determination . Question: What's the main idea of this passage? - Building schools can help people to have a better life. - We have to do something in return to those who help us. - Ordinary people can make a difference to people's lives. - Climbing mountains is a good start to help poor people.
The answer to this question is:
Ordinary people can make a difference to people's lives.