It's Sunday. There are many people in the bus. And an old man is looking here and there. He wants to find an empty seat . Then he finds one. He goes to it. A small bag is on the seat. And a young man is sitting beside it. "Is this seat empty?" asks the old man. "No, it's for a woman. She goes to buy some bananas." Says the young man. "Well," says the old man, "Let me sit here please. When she comes back, I will  leave here." The bus starts . "She doesn't come, but her bag is here. Let me give her the bag." Then the old man throws the bag out of the bus window. The young man jumps up and shouts, "Don't throw! It's my bag!" The young man says the seat is for   _  .
a man a woman a boy a girl