article: One morning, Sam went to school by bus. It was a long way, so he wore a Bluetooth earphone  to listen to music.
  Suddenly, an old woman went up to him and said quietly, "Good morning, sir!" He was surprised but asked in a friendly way, "What's up, Madam?"
  The old woman didn't answer him. But she looked happy and turned to an old man next to her and said loudly, "You see. His audiphones   must be pretty great. I said in a quiet voice, but he could still hear me."
  Sam got even more surprised. He didn't know what happened. Just then, the old man moved quickly to him and asked: "Excuse me, young man. In which store can I buy the audiphones you're using?"
question: Where did the story happen?
options: On a bus. On a train. In a store. In a school.