Which property of matter influences the speed at which waves move through it?
mass

Density

Volume

Electric charge

Density

Explanation:

Waves are periodic disturbances that travel in a medium by carrying energy without carrying matter.

There are two types of waves:

- Mechanical waves: these are produced by the vibrations of the particles in a medium. An example of mechanical waves are sound waves. Mechanical waves can only propagate through a medium, while they cannot travel in a vacuum.

- Electromagnetic waves: these consist of the oscillations of electric and magnetic fields in a direction perpendicular to the propagation of the wave. These are the only type of waves that can travel in a vacuum, since they do not need a medium.

The speed of a wave is the speed at which the wave propagates through the medium / the vacuum.

For mechanical waves, the speed of a wave in a solid material is given by

where

B is the  bulk modulus of the medium

is the density of the medium

Therefore, from the formula we see that the wave speed depends on the density of the medium, while the other quantities (volume, electric charge) are not involved.

For liquids and gases, the wave speed is obtained through a different formula, however it still depends on the density of the material. So the correct answer is

a) Density