Which statement correctly compares earthquakes at mid-ocean ridges and plate boundaries?

a) Earthquakes at mid-ocean ridges are less frequent than earthquakes at plate boundaries.

b) Earthquakes at mid-ocean ridges are more powerful than earthquakes at plate boundaries.
c) Earthquakes at mid-ocean ridges occur exclusively at transform plate boundaries.
d) Earthquakes at mid-ocean ridges are caused by volcanic activity, while earthquakes at plate boundaries result from tectonic plate interactions.

The correct statement is:

d) Earthquakes at mid-ocean ridges are caused by volcanic activity, while earthquakes at plate boundaries result from tectonic plate interactions.

At mid-ocean ridges, earthquakes tend to be shallow and less powerful, while at plate boundaries, earthquakes occur at various depths and can have varying magnitudes.