Concept:Coal-fired power stations release sulphur dioxide as a major pollutant because coal contains sulphur impurities.
Explanation:Coal is a fossil fuel that often contains sulphur compounds.
During electricity generation, the coal is burnt in air.
The sulphur in the coal reacts with oxygen to produce sulphur(IV) oxide gas,
SO2.
This gas is released into the atmosphere as an acidic pollutant.
So a city that depends on coal for electricity will usually have sulphur(IV) oxide in its air.
Other pollutants like carbon(II) oxide may also appear from incomplete combustion, but sulphur(IV) oxide is the typical coal-related pollutant.
Answer:D. sulphur(IV) oxide