I spent few days going through the verbal questions here and noticed that some questions, in my opinion, were not, so to speak, well rounded.
The reason I am saying this is that people who solve questions that do not strictly conform to real GMAT principles can develop bised thinking that can really hurt them on the exam (eg overanalyzing, using 'non-GMAT' pronciples, etc)
This problem particularly concerns verbal questions and not math (the latter can be easily proved or disproved).
Please state the source, so we can judge the reliability of the questions posted. This will also allow us to verify the right answer. And if someone made up a question himself/herself, please say so.