The speed of a wave depends on the
a. crest
c. medium
b. pitch
d. amplitude

Wave is a disturbance in a medium that transmits the energy between the two points. The medium is the material that wave travels through like water, air or gas. As the wave propagate, they disturb the density of the medium.

The medium and the speed of wave has a direct relationship. The higher the density of the medium, the higher the speed and as the density of medium goes lower so as the speed of the wave. The speed of the wave depends on the density of the medium.
C. Medium

It's true it didin't work becouse britain continued trading with it's colonies and the system hurt economies of the countries that used it