A certain airport security scanner designed to detect explosives in lu

IMO ANSWER E:

This is how: acc to the premise, the scanner will show 1% of false positive for all non-explosive luggage

Let's take nos: 100 non-explosive pieces of luggage, the scanner will result in 1 case of False positive but based
on this information, we cant deduce the accuracy for all the luggage which contain explosives as we have
info available for the accuracy of false + for non-explosive Luggage

A certain airport security scanner designed to detect explosives in luggage will alert the scanner’s operator whenever the piece of luggage passing under the scanner contains an explosive. The scanner will erroneously alert the operator for only one percent of the pieces of luggage that contain no explosives. Thus in ninety‑nine out of a hundred alerts explosives will actually be present.

The reasoning in the argument is flawed because the argument

(A) ignores the possibility of the scanner’s failing to signal an alert when the luggage does contain an explosive - WRONG. There is no discussion about not alerting but only about false alert and that too when explosive is no there.

(B) draws a general conclusion about reliability on the basis of a sample that is likely to be biased - WRONG. There is no bias as such but a conclusion based on some fact.

(C) ignores the possibility of human error on the part of the scanner’s operator once the scanner has alerted him or her - WRONG. Irrelevant.

(D) fails to acknowledge the possibility that the scanner will not be equally sensitive to all kinds of explosives - WRONG. Not the case here.

(E) substitutes one group for a different group in the statement of a percentage - CORRECT. No explosive to explosive conclusion.

Answer E.