Why Correct: Plate tectonics theory explains mountain formation through continental collisions, seafloor spreading at mid-ocean ridges, and earthquakes at plate boundaries.
Distractor Analysis: Mountain formation occurs at convergent boundaries where plates collide. Seafloor spreading happens at divergent boundaries where plates move apart. Earthquakes result from stress release at transform and other plate boundaries.
Takeaway: The theory unified earlier concepts of continental drift and seafloor spreading, explaining global geological phenomena through lithospheric plate movements.