Answer:
a. a quicksand-like condition arising in some wet soils during earthquakes.
Step-by-step explanation:
Liquefaction is a phenomenon that occurs when saturated soils start behaving like liquid. An earthquake can trigger this phenomenon with vibrations that breaks down soil stiffness. Because soil particles rely on each other to stay in place, the change in stress between them causes them to lose grip.
Liquefaction can cause a lot of damage, especially to infrastructures that are build on them. When soil lose strength, they may not be able to carry the structure above them and cause it to collapse.