Answer:
Transverse
Explanation:
Electromagnetic waves don't depend on the medium they travel through like a mechanical wave does, so they aren't mechanical. They don't oscillate (move back in forth) in the direction they travel either, ruling out compressional and longitudinal waves.
That leaves tranverse waves, the ones we're most used to, since they look very "wavelike," with smooth peaks and valleys. Electromagnic waves behave like these, oscillating in a plane perpendicular to the direction they're traveling in.
