You are presented with the question "What can human ears hear?" and the following answer choices: 
- radio
 - time
 - waves
 - Frogs
 - Frogs.
 - light
 - xrays
 - sound

Now knowing that aradio converts electrical energy into vibrations and ordinary hearing is the result of the stimulation of bones in the inner ear by means of vibration, choose the best answer.


 

 radio        