Answer:
Solids
Step-by-step explanation:
They cannot travel through liquids and gases. However, P-waves can. The reason S-waves cannot travel through liquids and gases is that these mediums lack shear strength (remember S-waves are also referred to as shear-waves because particles in this wave move perpendicular to direction of wave). S-waves need a rigid medium or them to propagate.
S-waves are also slower than P-waves. They travel at speeds of range between 1 and 8 km/s. P-waves can reach speeds of 14km/s.