Harry is eight years old. He goes to school near his home. He always goes there and comes home on foot. One day he came home from school late. His mother saw him and asked him, "Why were you late, Harry?" "My teacher was very angry and asked you to go to her office tomorrow." "To her office? Why?" his mother asked. "Because she asked a question in the class." said Harry. "Nobody could answer it, but I could. " "You are so clever, my son. " his mother said with a smile." What is her question?". Her question is "Who put the tomato on my chair and made my trousers dirty?" said Harry. The teacher's trousers were dirty because   _  .
she sat on the ground it was raining hard . she sat on the tomato she had it for a long time