Fact 1: Telephones are used for communication by two people by transmitting sound.

Fact 2: When a wave is audible, it is called a sound wave .

Given the two facts above, answer the question "Telephones are used for communication by transmitting what?" with the following options: 
- encoded information
 - Electrical energy
 - music
 - chemical messengers
 - telephone messages
 - audible waves
 - pictures
 - electricity


 

      audible waves   