Which musical notes can be perceived by the human ear? Which musical notes combine to be the most beautiful? Which frequencies can be heard by children but not by adults? Which frequencies can be produced by human vocal cords?
I gave my students this multiple choice question: Which of these questions cannot be answered scientifically?

Only one answer is correct among these 4 choices:
- Which musical notes can be perceived by the human ear?
- Which musical notes combine to be the most beautiful?
- Which frequencies can be heard by children but not by adults?
- Which frequencies can be produced by human vocal cords?

Could you tell me which one is correct?

Which musical notes combine to be the most beautiful?