
The Correct choice is : C. <u>Solids</u>
Sound waves need a medium to propagate, and the most suitable medium for that is solids, where it travel the fastest or with greatest efficiency.
Bodies of water often were used to create borders EX: in the eastern united states the states borders are rivers because it is easier than making imaginary borders
US Attractions
Graceland. Graceland is one of the most visited houses in the United States, attracting over 600,000 visitors each year. ...
Pink Palace Museum. ...
Country Music Hall of Fame. ...
Great Smoky Mountains National Park. ...
Montgomery Zoo. ...
Old Alabama Town. ...
The US Space and Rocket Center. ...
Alabama Jazz Hall of Fame.
D. Rolling hills . Its usally Plateu but I gusse rolling hills would work too