- Carpet has a rough surface
- A rough surface can absorb sound
- Therefore, a carpet can absorb sound

- A carpet can absorb sound
- If sound is absorbed, then sound can not reflect off the surface
- Hence, sound cannot reflect off the surface of a carpet

- The statement "Building terraces increases the amount of terraces in an environment " is irrelevant

- Sound cannot reflect off the surface of a carpet
- Echo is when sound reflects off a smooth surface
- Hence, echo will not be produced

So, echo will not be produced
Question
Which of these materials on the walls of a room would work best to keep sound from making an echo?

Context
- Echo is when sound reflects off a smooth surface 
- Building terraces increases the amount of terraces in an environment 
- Carpet has a rough surface 
- A rough surface can absorb sound 
- If sound is absorbed, then sound can not reflect off the surface