Here's a problem to solve: Which of these questions cannot be answered scientifically?

Among the 4 following options, which is the correct answer?

- A: Which musical notes can be perceived by the human ear?
 
- B: Which musical notes combine to be the most beautiful?
 
- C: Which frequencies can be heard by children but not by adults?
 
- D: Which frequencies can be produced by human vocal cords?
 