What Causes Swelling Soils to Swell

Multiple Choice

What causes swelling soils to swell?

A) When they get wet, water enters the clay mineral structure to cause swelling.
B) The presence of abundant kaolinite clay takes water in between its layers.
C) When water in clay-rich soil freezes, the soil swells.
D) When an earthquake shakes wet soil, more water can get between the grains to cause swelling.
E) Landsliding of a mass relieves pressure on soil, permitting it to expand.