Mismatched premises and conclusion. (A) presents someone’s opinion in the form of a conditional statement (if the surgery were performed by a highly skilled surgeon, then the patient would probably survive). The conclusion then invalidly brings up the new idea of the surgery not being properly performed. The stimulus, however, features a conditional statement without the word “probably” and brings up no new information in the conclusion, so (A) doesn’t match.

Mismatched premises. (B) presents someone’s opinion (the sample probably did not contain organic compounds), but this is not a conditional statement. The conditional statement that is presented is instead stated as a fact. The stimulus, however, presents a conditional statement as an opinion, so (B) doesn’t match.

(C) proceeds by presenting someone’s opinion in the form of a conditional statement (if the wall were properly repaired, then the damage would not be noticeable). It then concludes that the absence of the necessary condition (the damage being noticeable) probably leads to the absence of the sufficient condition (the wall not being properly repaired).

Mismatched conclusion. (D) presents a conditional statement in the form of a builder’s opinion (if the roof was not damaged in a storm, then it would not require repairs for a while). It then presents the presence of the sufficient condition and the absence of the necessary condition to conclude that the builder’s opinion is wrong. The stimulus, however, presents someone’s opinion without ever disputing its accuracy, so (D) doesn’t match.

(E) presents someone’s opinion in the form of a conditional statement (if the tests were properly conducted, then they would find lead in the soil). It then concludes that the presence of the necessary condition leads to the presence of the sufficient condition. The stimulus, however, presents someone’s opinion in the form of a conditional statement before concluding that the absence of the necessary condition leads to the absence of the sufficient condition, so (E) doesn’t match.