Premise - The recent increase in the number of persons suffering from illnesses is attributed to excessive air pollution.
Conclusion - The non urban areas are
now affected with air pollution.
Prethink - The conclusion relies on the number of person suffering from illness.
Assumption - The recent increase in the number of persons suffering is
primarily due to the illness of non-urban people.
To weaken the argument's conclusion, we should look for the choice that goes against this assumption.
Quote:
Another way to weaken is to bring a doubt to the accuracy of the premise that results the conclusion
(A) The nation’s cities have seen a marked decrease in levels of air pollution.
The conclusion relies on the increased number of person suffering from illness.
If cities have seen a marked decrease in levels of air pollution and we are sure that there is an excessive air pollution, we must believe that the air-pollution affected the non-urban areas. Strengthen the conclusion. (B) The nation has experienced a sharp decrease in the number of people moving out of its cities.
The premise says about the total increase in the number of persons suffering from illness.
This option actually just says that the number migrating outside the cities is much lesser (but still the total got increased). Hence,the number increased either within the city or non urban areas. Nothing else can be concluded. (C) Illnesses due to air pollution are among the
least common causes of death to urban dwellers.
The severity of illness is not a concern. (D) Many illnesses previously thought unrelated to air pollution are now considered to be caused by it.
It actually says that the the increase in the number might not be actually because of excessive pollution but because of the way the cause was considered. Weakens the cause of the conclusion that non urban areas are now affected with air pollution.(E) As a result of the problems in urban areas, nonurban areas have passed strict pollution control measures.
What happened to the measures? did they succeed? We don't know. We can't comment the current situation of non-urban areas. Quote:
Note - Precautions taken against an issue can't help to conclude anything about the issue.
IMO
D