A recent study has revealed, through meticulous research, a link between the harmful hydrocarbons in air pollutants and the IQ test scores of children. The research involved measuring the quality of air that pregnant women breathed during the third trimester of pregnancy, and then following the children born from that pregnancy until an IQ test could be administered. Many external factors were taken into consideration, such as the mother's IQ and the family's home environment with regards to intellectual development. Health officials, having studied this information, plan to tackle the phenomenon by increasing public awareness on the matter through campaigns aimed at warning parents-to-be.

In the argument, the two portions in boldface play which of the following roles?

A) The first associates a cause with an effect; the second demonstrates the reasoning behind the formation of such an association.
B) The first is a relationship contradicted by the conclusion; the second is factual information that supports that conclusion.
C) The first is the result of an analysis; the second weakens the possibility of doubt with regards to the accuracy of that analysis.
D) The first is a correlation between two entities; the second is evidence that directly strengthens the existence of that correlation.
E) The first offers a logical connection between two factors; the second indicates a possible flaw in the credibility of that connection.

OA C

Source: Economist GMAT