People sometimes like to read stories of dogs very much. They think that dogs are much cleverer than cats, sheep, cows or other animals in their homes. One of my best friends, Bob, has a dog named Jack. Every Sunday afternoon, Bob and Jack have a walk in the park nearby. Jack likes these walks very much. One Sunday afternoon, I stayed in Bob's home for a long time and we talked happily. Soon it was time for them to take a walk in the park. Jack was worried about it. He walked around the room several times and then sat down in front of me and looked at me. But I still paid no attention to him. I went on talking with my friend. At last, Jack could not wait any longer. He went out of the room and came back a few minutes later. He sat down in front of me again. But this time, he held my hat in his mouth. Suddenly, I understood what Jack meant. How many people are there in this story? _ . A) One B) Two C) Three D) Four
B