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

Fact 2: Sound Sound waves are mechanical waves.

Given the two facts above, answer the question "what do people transmit when using telephones for communication?" with the following options: 
- internet signals
 - diseases
 - fibers
 - SNPs
 - power
 - waves
 - energy
 - h2o


 

      waves   