Please, please help
During the process of mountain building, earthquakes sometimes occur along continental-continental convergent boundaries. Which statement best describes the motion of the plates along these boundaries that causes the earthquakes?

The plates push apart from each other with no subduction.
Subduction occurs with the less-dense plate sinking below the other plate.
Subduction occurs with the more-dense plate sinking below the other plate.
The plates smash together with no subduction.