What did they do after lunch?

Choose the letter A, B, C or D to answer these following questions
Last week Nick and some of his classmates went to the countryside. They went to visit a farm of Nick’s uncle.
They left early in the morning and went there by bus. Nick’s uncle, Mr. Brown met them at the bus stop and took them to his farm. On the way, Uncle Brown showed them the field of wheat and vegetables where some tractors were running up and down, ploughing and breaking soil, distributing manure and planting potatoes.
After lunch, they all went for a walk. In the large yard of the farm, they saw some farm machines. Among them is the biggest machine which is called a combine harvester. They were told that this machine can cut and thresh corn at the same time.
In the afternoon, they went to the paddy field, the place where cattle such as horses, sheep and cows were raised. They were very excited to see how cows were milked by the workers there. Uncle Brown also spoke about many interesting things in the countryside. After having some fruits and cakes, they said goodbye and went home.