Question

The source(s) of sulfur dioxide in the atmosphere is/are _____________.

A.
bacterial action

B.
fossil-fuel combustion

C.
volcanic activity

D.
forest fires

E.
all of the above

Answer 1

This is formed from Sulfur or any other sulfur containing material...

Note that in reality, we may obtain this via:

bacterial action --> some bacteria use Sulfur instead of Oxygen (anaerobic bacteria) as its oxidant material

fossil-fuel combustion --> plenty of fossils are rich in sulfur, therefore they produce an oxygenation state of Sulfurs (i.e. Sulfur oxides)

volcanic activity mainly --> this is the natural source of SO2 from previous milenia. It is also due to the Sulfur contained in the earth's crust

forest fires --> very low sulfur emission, but still considered important in huge forest fires

therefore

choose "E" which is all of above