Please answer the following question: Write a multi-choice question for the following article, with the given choices and answer: Article: Now many boys wear the same clothes as girls, and some of them have long hair. So sometimes it's difficult to tell whether they are boys or girls. One Sunday morning, I went for a walk with my grandfather in the park near my house. After a while, my grandfather was tired, so he sat down on a bench near the pool. "Oh," my grandfather said to the person with long curly hair next to him on the bench. "Can you see the person with long hair on the other side of the pool? Is it a boy or a girl?" "Which one?" asks the person with long curly hair. "The one who is eating a hamburger near the pool," said my grandfather. "He is a boy," said the person, "he's my son, Han Han." "Oh," my grandfather said, "I'm sorry, I don't know you are his mother." "No, I'm not his mother. I'm his father." Options: A went shopping B went swimming C went for a walk D went to the bank Answer: C went for a walk Question:
A:
One Sunday morning, the writer's grandfather _ .