Question

multiple - choice question
what causes volcanoes to errrupt?
they dont erupt
hard rock getting trapped at the surface
a build up of gases trapped by magma
rewatch

Explanation:

Volcanoes erupt due to a build - up of gases (such as water vapor, carbon dioxide, and sulfur dioxide) trapped by magma. When the pressure from these gases becomes too high, it forces the magma to the surface. The option "They don't erupt" is incorrect as volcanoes do erupt. "Hard rock getting trapped at the surface" is not the main cause of eruptions.

Answer:

A build up of gases trapped by magma