Feng Shui Video of Tian Li Village, jiaomei

Burning straw in the open air will produce harmful gas and smoke, and the option is wrong;

Changing from using coal stoves to using natural gas for home cooking will improve air quality, so the choice is correct;

Nitrogen dioxide mainly comes from incomplete combustion of fossil fuels and automobile exhaust, so the choice is wrong;

The rapid increase in the number of private cars will produce carbon monoxide and smoke, so the choice is wrong;

Therefore, choose: B.