conclusion questions- > use scope based approach.
1. Most examinees with inconclusive polygraph test results are infact untruthful. [this is not implied in the stimulus. It infact says inconclusive P test bears no reflection on examinee. Eliminated!]

2. Polygraph tests should not be used by employers in the consideration of job applicants. [this is a strong word. The stimulus no where uses this strong indication. Also note- the stimulus says employers will sometimes. so can something that applies to sometimes be generalized for always? Eliminated!]

3. An inconclusive polygraph test result is sometimes unfairly held against the examinee. [This correctly takes the probability indicator- sometimes in account. It also mentions that it is unfairly held against examinee. Correctly within the scope of the argument. My answer]

4. A polygraph test indicating that an examinee is untruthful can sometimes be mistaken. [our stimulus talks about case when P test is inconclusive. We do not deal with what happens when P test finds an examinee untruthful. New topic error. Eliminated!]

5. Some employers have refused to consider the results of polygraph tests when evaluating job applicants.[ New topic error again. our stimulus does not deal with cases when examiners do not consider P test at all. we are bothered abt examiners who consider P test and sometimes unfairly hold the inconclusive test results against the examinee. Eliminated!]

Note: in such question, we need to look at only the stimulus. There is no scope for any other extra info other than what is given in the stimulus to appear in the answer choices.

Hope this helps!