You are making a telephone out of two aluminum cans and some string. You can choose between two types of string: a 2-m length of thin cooking twine or a 2-m length of heavy rope, both used at the same tension.
Which type of string should you use so that you have the fastest wave speed in your telephone?

a. You should use the thin cooking twine.
b. You can choose either because they are the same length and will produce the same wave speed.
c. You should use the heavy rope.