Answer: Volcanoes
Step-by-step explanation:
The Earth's tectonic plates are always moving and as a result come into contact with each other at their boundaries.
These boundaries are where the majority of volcanoes are formed because of the movement of the plates allowing for magma to flow upwards from the mantle.
Divergent plate boundaries see plates moving away from each other and this gives magma an opportunity to rise from the mantle. Convergent plate boundaries have plates hitting each other which causes magma to rise when one plate sinks into the mantle.
As the magma rises, volcanoes are formed when the magma cools.