The tenth five-day weather in Jinmeng

A, the improvement of oil quality will reduce the emission of exhaust pollutants; Therefore, A is correct;

B, increasing the chimney height can reduce the content of SO2 and dust on the surrounding surface, but the total amount of SO2 emission remains unchanged, which is not absorbed and removed, and it is easy to expand the pollution range by Z, so it cannot reduce the harm of smog weather to human beings; Therefore, B is correct;

C. Sprinkling water on the construction site and road surface in time can also reduce air pollution; Therefore, C is correct;

D, coal combustion is the main fuel of thermal power generation, and Z amount of CO, NO2, SO2 and inhalable particles will be produced during coal combustion, so D is wrong;

So the answer is: a.