Which cycle causes earthquake and volcanic activity?

Answer: Plate techtonics is the movement of the lithospheric plate over the underlying mantle. The results in the breakage of lithospheric plates into number of plates which floats and travel in the surface of Earth's mantle. This occurs due to geological processes like earthquakes and volcanic activity.

Explanation:?

Earthquakes occur when Earth's slow-moving tectonic plates suddenly slip against one another, usually due to a build up of stress that destabilizes the two

Volcanoes are formed by eruptions of lava and ash when magma rises through cracks or weak-spots in the Earth's crust