Which one of the following is given by the passage as a reason for the difficulty a lawyer would have in determining ...

I think the explanation on question 4 may be slightly incorrect. The passage implies that if you are intelligent that you cannot be wise, and if you are wise that you cannot be intelligent. They way hit is explained and diagrammed is that if you are not wise that you must be intelligent, and that if you are not intelligent that you must be wise. I believe the explanation mistakes the sufficient and necessary terms in the last sentence of the passage.