Respiration can be defined as the process in which exchange of gases occurs between organism and their environment.
For example, the plants get its energy through the process of respiration in which glucose is broken down into carbon dioxide and water with the release of energy in the presence of oxygen. This energy is then used by the plant for carrying out its various life processes.
The answer is (A) as <span> increasing risk of lung cancer is from increasing levels of exposure to outdoor air pollution and </span>particulate matter
