For many years people in Estonia have been leaving their rubbish in the forests. Rainer Nolvak, a businessman and his friends wanted to clean up all the rubbish in Estonia. The rubbish was not just an environmental problem. It was a problem of people's attitudes. Rainer Nolvak got together with a team of 20 friends and they began to make a plan about how to clean up the rubbish. Soon, over 600 people joined in the group. They named the project  Let's Do It! Estonia. The Ministry of the environment gave them some support. Many other companies joined in the group. Famous actors and singers also took part. Even the President of Estonia joined in. They sent information about Let's Do It! Estonia throughout the country. Technology experts developed a special computer program. Team members went into the forests to find where the rubbish was. They used their mobile phones to mark every place where they found rubbish and send the information to the computer program. Then, the marked rubbish places appeared on the map. Anyone could go on the Internet and see the map. The team found a surprising result. There were over 10,000 tons of waste in the forests of Estonia. When people saw how much waste was around their own homes, they were shocked. Thousands of people began to help. The team chose May 3, 2008 as the day to clean up the rubbish. On May 3, more than 50,000 people helped to get rid of the rubbish. They moved over 10,000 tons of rubbish in only one day!     This was amazing for the environment in Estonia. But it was also an important step for Estonian society. Rainer Nolvak gave a speech at a conference in the Balkans. He said: "The most important thing we did was build a team. It changed every one of us. We had to connect to people. We had to see that the rubbish was our problem. At times we are afraid of sharing. When we are together and there are many of us, we are not afraid.' The Project Let's Do It! Estonia is to   _  .
prevent people leaving their rubbish anywhere make Estonia a clean place change people' s attitudes towards the environment make plans for businessmen
Question: For many years people in Estonia have been leaving their rubbish in the forests. Rainer Nolvak, a businessman and his friends wanted to clean up all the rubbish in Estonia. The rubbish was not just an environmental problem. It was a problem of people's attitudes. Rainer Nolvak got together with a team of 20 friends and they began to make a plan about how to clean up the rubbish. Soon, over 600 people joined in the group. They named the project  Let's Do It! Estonia. The Ministry of the environment gave them some support. Many other companies joined in the group. Famous actors and singers also took part. Even the President of Estonia joined in. They sent information about Let's Do It! Estonia throughout the country. Technology experts developed a special computer program. Team members went into the forests to find where the rubbish was. They used their mobile phones to mark every place where they found rubbish and send the information to the computer program. Then, the marked rubbish places appeared on the map. Anyone could go on the Internet and see the map. The team found a surprising result. There were over 10,000 tons of waste in the forests of Estonia. When people saw how much waste was around their own homes, they were shocked. Thousands of people began to help. The team chose May 3, 2008 as the day to clean up the rubbish. On May 3, more than 50,000 people helped to get rid of the rubbish. They moved over 10,000 tons of rubbish in only one day!     This was amazing for the environment in Estonia. But it was also an important step for Estonian society. Rainer Nolvak gave a speech at a conference in the Balkans. He said: "The most important thing we did was build a team. It changed every one of us. We had to connect to people. We had to see that the rubbish was our problem. At times we are afraid of sharing. When we are together and there are many of us, we are not afraid.' The Project Let's Do It! Estonia is to   _  .
A. prevent people leaving their rubbish anywhere
B. make Estonia a clean place
C. change people' s attitudes towards the environment
D. make plans for businessmen
Answer: