Compare primary and secondary pollutants. which is more harmful?

Secondary pollutants are more harmful.

Explanation:

Air pollution can be defined as the presence of harmful substances present in the atmosphere more than the natural levels. Based on the source of emission they are classified into primary pollutant and secondary pollutant.

The pollutant that is released directly from the source either by natural causes  or man made causes is known as primary pollutant.

Example: Gases like sulfur dioxide, carbon dioxide, nitrogen oxide, et cetera.

The pollutants that is formed by the physical or chemical interaction among the primary pollutant or due to the interaction between the primary pollutant and other components of the atmosphere is known as secondary pollutant.

Example: Ozone.

Secondary pollutant is more harmful as compared to that of primary pollutant because they are not present in the original form and is not reduced easily.

the answer for this question would be d. glaciers

the darker peppered moth species were favored due to the fact that the industrial revolution had made all the nearby trees a darker color instead of white.