bkpolymers1617
The National Disease Control agency of Country X found in a recent review of statistics that the prevalence of malaria is twice as high in the western portion of the country as it is in the eastern portion of the country. If a newlywed couple from the high-malaria western portion of the country, therefore, were to move to the eastern portion in order to start their family, they could expect a lower likelihood that their children would contract malaria.
Which of the following, if true, would most weaken the conclusion drawn in the passage?
A) People who move from the western portion of Country X to the eastern portion are less likely to contract malaria than if they stayed in the western portion of Country X.
B) The head magistrate of the western portion of Country X has declared a state of emergency due to the high number of malaria cases in that area.
C) Most of those living in the eastern portion of Country X belong to a unique ethnic group that is genetically resistant to malaria.
D) Sixty percent of those living in the western portion of Country X will never contract malaria in their lives.
E) The western portion of Country X experiences more rain during the year; this in turn provides the standing water necessary for the hatching of malaria-causing mosquitoes.
Answer C.We are told there is a higher correlation between living in the western portion of the country and contracting malaria then there is with the eastern part - and the conclusion is based on assuming this correlation implies causation.
Since we need to
weaken, we will look for something which explains the west-malaria correlation by some other cause then the geographical location, such as the characteristics of the people who live there - their diet, lifestyle, genetics or something similar which could cause or prevent the sickness. This is
exactly what C gives us.
Solving by elimination:
A) this
strengthens the conclusion greatly - it literally states the conclusion is true.
B) This doesn't really add much, but rather s
imply repeats information we already know (there is a lot of material in the west).
C) This implies it may not be the location which causes few infections in the east, but something else (the ethnic group); thus, someone from a different ethnic group moving to the east may not be protected at all.
Weakens. D) This could perhaps be seen as weakening, but it isn't really: this information is meaningless without a comparison to the eastern part. And since we have already been told that the prevalence in the west is twice as high, this can't change that.
Irrelevant. E)
Strengthens the conclusion: this implies the correlation between west-malaria is indeed a causation (the weather conditions in the west cause the malaria), suggesting moving to the east can indeed reduce the risk.