Concept:Only transverse waves can be polarized because their vibrations occur perpendicular to the direction of travel.Explanation:In a transverse wave, particles vibrate at right angles to the direction of energy transfer.This allows the vibrations to be confined to a single plane, which is called polarization.In a longitudinal wave, particles vibrate parallel to the direction of travel, so polarization is not possible.Reflection, interference, and diffraction are common to both transverse and longitudinal waves.Answer:D. polarization