Which statement about UT wave types is correct?

• A. P-waves are compressional and travel slower than S-waves.
• B. P-waves are shear and travel faster.
• C. S-waves are compressional and travel faster.
• D. P-waves are compressional (particle motion parallel to travel) and travel faster; S-waves are shear (perpendicular) and travel slower.

Answer: (D)