Bunuel wrote:
Scientists have studied the effects of electromagnetic fields associated with high voltage power lines upon people whose homes are located within 300 yards of the lines. They have compared the growth rate of children who live near the lines with the growth rate of children who live elsewhere. Because they found no significant differences in the growth rates in the two study areas, they have concluded that electromagnetic fields are harmless.
Which one of the following, if true, would most seriously jeopardize the scientists’ conclusion?
(A) The scientists did not consider other possible impacts upon growth rates.
(B) In studying people who lived near high voltage power lines, the scientists did not consider what type of housing those people lived in.
(C) The growth rates of children have changed considerably since the 1920s.
(D) People who live near electromagnetic fields suffer health problems that are not reflected in the growth rates of their children.
(E) As children get older, their activities tend to occur away from home more often.
Official Explanation
(A) No. The study is concerned only with the effects of electromagnetic fields. Determining what other factors might impact children’s growth rates would be irrelevant to determining the effects of electromagnetic fields.
(B) No. Since the growth rate for both groups of children was the same, it does not appear that the type of housing was important in determining the effects of
exposure to electromagnetic fields.
(C) No. The growth rate of children in the 1920s is insignificant to the purpose of this study—to determine whether proximity to electromagnetic fields has any harmful effects.
(D) Yes. The scientists assume that the only negative effect from living near electromagnetic fields would be a lower growth rate in children. Perhaps adults and children who live near the lines suffer from other ailments. These would not be reflected in a study of children’s growth rates and thus, this statement, if true, would seriously jeopardize the scientists’ conclusion.
(E) No. Children’s growth rates were the same, so how much time children who lived near the power lines spent at home would appear to be irrelevant.
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