Concept:Wave motion is classified as transverse or longitudinal based on the direction of particle vibration relative to the direction of wave travel.
Explanation:Electromagnetic waves are transverse because their electric and magnetic fields oscillate perpendicular to the direction of propagation.
Transverse mechanical waves, such as waves on a string, do require a medium.
Longitudinal waves vibrate parallel to the direction of travel, not perpendicular.
Mechanical waves can be transverse or longitudinal, so not all are longitudinal.
Answer:A. Electromagnetic waves are transverse