Task: Question Answering
Input (English): When a transverse wave passes from right to left through a medium, what happens to the particles of the medium?  
 (A) Particles travel from right to left along the wave. (B) Particles travel from left to right along the wave. (C) Particles move back and forth parallel to the wave. (D) Particles move back and forth perpendicular to the wave.
Output (English): D