* Mechanical Waves: These require a medium (like air, water, or a solid) to travel.

* Transverse Waves: The particles in the medium move perpendicular to the direction the wave travels. Examples: light waves, water waves.

* Longitudinal Waves: The particles in the medium move parallel to the direction the wave travels. Examples: sound waves, seismic P-waves.

* Electromagnetic Waves: These do *not* require a medium and can travel through a vacuum. They are always transverse. Examples: radio waves, microwaves, visible light, X-rays.

To answer your question, you need to provide a list of options!

For example, if your options were:

* Sound waves: This is a mechanical longitudinal wave.

* Light waves: This is an electromagnetic transverse wave.

* Water waves: This is a mechanical transverse wave.

* Radio waves: This is an electromagnetic transverse wave.

* Gravity waves: This is a special type of wave that does not fit neatly into the categories above. It's caused by disturbances in spacetime itself.

Let me know your options, and I can tell you which one doesn't fit the categories.