Answer:
Option D.
Explanation:
In most areas of these 2 countries, the woodburning fireplaces are responsible for about 75% of particulate matter air pollution generated by residential sources.
These emissions have also been proven to contain carbon monoxide, nitrogen dioxide, sulfur dioxide and even chemicals suspected to be carcinogens. Prolonged exposition to these toxic gases may cause people to develop breathing affections.
Further studies have also demonstrated that prolonged exposition to woodsmoke has caused animals to decrease their disease resistance, and the same could be said about humans.