In an attempt to discover the cause of malaria, a deadly infectious disease common in tropical areas, early European settlers in Hong Kong attributed the malady to poisonous gases supposed to be emanating from low-lying swampland. Malaria, in fact, translates from the Italian as “bad air.” In the 1880s, however, doctors determined that Anopheles mosquitoes were responsible for transmitting the disease to humans. The female of the species can carry a parasitic protozoan that is passed on to unsuspecting humans when a mosquito feasts on a person’s blood.

What functions do the two statements in boldface fulfill with respect to the argument presented above?

(A) The first follows from a mistaken conclusion about a topic in question; the second explicates the correct explanation of that topic.
(B) The first provides an initial conjecture; the second presents evidence that contradicts that conjecture.
(C) The first serves to illuminate a contested assumption; the second offers confirmation of that assumption.
(D) The first identifies the cause of an erroneous conclusion; the second develops a premise to support the correct conclusion.
(E) The first provides detail about the original, and incorrect, school of thought; the second ,provides the judgment later found to be true.

Kudos for R.A.E