Which statement correctly compares the motion of the particles of a medium with the transmission of a sound wave through that medium?
(a) Particles travel along the medium with the same speed as the sound wave.
(b) Particles vibrate about their positions while the disturbance moves forward.
(c) Particles move at right angles to the direction in which the disturbance travels.
(d) Each particle ends up one wavelength away from its starting point as the wave passes.