Describes all the processes associated with the discharge of magma, hot fluids, ash, and gases

I'm almost certain it would be volcanism.

C. naturally in the environment

Aregion is an area of land that has common features. these features can be natural, such as climate or landscape. they can also be artificial, such as language or religion. the xinjiang uyghur autonomous region, above, is an area of china inhabited by uyghurs, a muslim group with ethnic ties to turkish people.