The slowest type of mass movement, which involves the lifting and contracting of soil particles over time, is called

a.) a rockslide
b.) an earthquake
c.) creep
d.) rockfall

I think the correct answer from the choices listed above is option C. The slowest type of mass movement, which involves the lifting and contracting of soil particles over time, is called creep. It is a slow downslope movement of particles that occurs on every slope covered with loose, weathered material. Hope this answers the question.