The wave that moves matter at right angles to the direction it travels is a transverse wave.

Here's why:

* Transverse waves have oscillations that are perpendicular to the direction the wave travels. Think of a rope tied to a post. If you shake the rope up and down, the wave travels horizontally, but the rope itself moves vertically.

* Longitudinal waves, on the other hand, have oscillations that are parallel to the direction of wave travel. An example is a sound wave, where the air molecules compress and expand in the same direction the sound is traveling.

Let me know if you'd like more examples of transverse waves!