Answer
(b)
Work Step by Step
Pyrite ($FeS_2$), also known as "fool's gold", is commonly found in mining areas.
When exposed to air and water, pyrite undergoes oxidation, producing sulfuric acid and iron ions.
These iron ions can precipitate as iron hydroxides, which give the water a distinct yellow to orange color — a phenomenon known as acid mine drainage.
The answer is (b).
