In the united states and canada, the most common problem with using wood as a major heat source is: a. the cost. b. wood shortages. c. that it separates people from the utility grid. d. the production of pollutants. e. using wood as an alternate source is a viable way to reduce our dependence on foreign oil. f. none of these.

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.

answer; i believe the best and correct answer is stronger bonds between the nations of africa;