Fact 1: Aradio converts electrical energy into vibrations.

Fact 2: Sound Sound waves are caused by vibrations in the air.

Given the two facts above, answer the question "What creates sound waves?" with the following options: 
- a curling iron
 - energy
 - carpet
 - animals
 - dolphins
 - Gunshots
 - a couch
 - a radio


 

        a radio 