Impressions made by the ridges on the ends of the fingers and thumbs are useful means of identification, since no two persons have the same pattern of ridges. If finger patterns from fingerprints are not decipherable, then they cannot be classified by general shape and contour or by pattern type. If they cannot be classified by these characteristics, then it is impossible to identify the person to whom the fingerprints belong.
Explanation
Answer: C - This question asks for the response option that cannot be validly concluded from the information in the paragraph. The only response option that cannot be validly concluded is Response C, so the correct answer to question 7 is Response C. Response C is invalid because the paragraph does not provide enough information to conclude whether or not it would be possible to identify the person to whom the fingerprints belong from the mere fact that the fingerprints are decipherable.
Response A refers to a condition where it is possible to identify the person to whom fingerprints belong. Based on the final sentence in the paragraph, this condition of fingerprints means that the fingerprints could be classified by general shape and contour or by pattern type. Based on the second sentence, the ability to classify the fingerprints means that the fingerprints are decipherable.
Since Response B refers to a condition in which finger patterns from fingerprints are not decipherable, we know from the second sentence that, in that circumstance, they cannot be classified by general shape and contour or by pattern type. From the final sentence in the paragraph, we can infer that since they cannot be classified by these characteristics, then it is impossible to identify the person to whom the fingerprints belong.
According to the second sentence, fingerprints cannot be classified by general shape and contour or by pattern type when they are not decipherable. Therefore, if fingerprints can be classified by general shape and contour or by pattern type, then the fingerprints must be decipherable, Response D. According to the third sentence, it is impossible to identify the owner of a set of fingerprints when the fingerprints cannot be classified by general shape and contour or by pattern type. Therefore, if it is possible to identify the person to whom fingerprints belong, then the fingerprints must be able to be classified by general shape and contour or pattern type, Response E. Notice that Responses D and E are valid based on the same type of reasoning. The first and second statements of the second sentence were made opposite and reversed in Response D, and the first and second statements of the final sentence were made opposite and reversed in Response E.
