Fact 1: Blowing air into a whistle causes air to vibrate inside the whistle.

Fact 2: When an object moves or vibrates, the air molecules around the object also vibrate.

Given the two facts above, answer the question "Blowing air into what causes air to move inside it?" with the following options: 
- heat
 - solid plastic
 - solid glass
 - solid rock
 - whistle
 - sound
 - a chime
 - waves


 

     whistle    