@CamilleChmura I try to make the argument less explicit -- replace the words with variables like A and B or use other words to explain the stimulus' form. If you can correctly identify the form of logical reasoning, then it'll be easier to identify the correct answer because only one answer will mirror the form. In this question, the conclusion of the stimulus basically said "the person who stole the diamonds had to be anyone other than Mr. Tannisch," or in other words the stimulus' conclusion ignored the evidence in the premise. The correct answer was the only one that ignored the evidence of the premise in making its conclusion.
@CamilleChmura I try to make the argument less explicit -- replace the words with variables like A and B or use other words to explain the stimulus' form. If you can correctly identify the form of logical reasoning, then it'll be easier to identify the correct answer because only one answer will mirror the form. In this question, the conclusion of the stimulus basically said "the person who stole the diamonds had to be anyone other than Mr. Tannisch," or in other words the stimulus' conclusion ignored the evidence in the premise. The correct answer was the only one that ignored the evidence of the premise in making its conclusion.