Where do most earthquakes and volcanoes occur?

Most earthquakes and volcanoes occur along the edges of tectonic plates due to the movement of these plates. The Earth's lithosphere is divided into several large and small tectonic plates that are constantly shifting, leading to various geological activities.

At the boundaries where these plates interact, different types of stress can build up, resulting in either volcanic activity or seismic activity, such as earthquakes. For example, when plates collide, one may be forced beneath another in a process called subduction, which can lead to volcanic eruptions and earthquakes. Other interactions, like plates sliding past each other (transform boundaries), are also responsible for significant seismic activity.

This pattern of geological processes explains why regions near plate boundaries, such as the Pacific Ring of Fire, are often the most active in terms of earthquakes and volcanism, while areas in the center of continents generally experience much less activity. Therefore, the correct answer underscores the crucial role that the edges of tectonic plates play in shaping Earth's geological landscape.