<u>Smoking</u> causes respiratory disorders such as bronchitis, pneumonia and lung cancer.
<u>Explanation:</u>
Respiratory disorders such as bronchitis, pneumonia and lung cancers are caused by smoking tobacco, air pollution and by infection. Smoking is the predominant cause of this respiratory order it also raises the level of air pollution which becomes hazardous to all the living organisms.
Infection in the lungs which is identified as pus in air sacs and found as inflamed lungs is usually life threatening. Severe shortness of breathe called the bronchitis is due to airborne chemicals.
I think the correct answer from the choices listed above is option C. The purpose of a controlled experiment is to examine whether one variable causes a change in another. A<span>n independent variable is the only factor that is allowed to be adjusted, with the dependent variable as the factor that the independent variable will affect.</span>
They are called Consumers I believe hope that helps ☺
