Question

which best describes electromagnetic waves?
sound waves that can only travel in a medium
transverse waves made up of electric and magnetic fields
longitudinal waves made up of vibrations that move through matter
mechanical waves that travel as ripples in water

Explanation:

Electromagnetic waves are transverse waves. They consist of oscillating electric and magnetic fields that are perpendicular to each other and to the direction of wave propagation. They do not require a medium (unlike sound waves, longitudinal waves that need matter, or mechanical water - ripples which are also mechanical and need a medium).

Answer:

transverse waves made up of electric and magnetic fields