(1) at most three conductive; means at least two non-conductive; we only need one non-conductive for no-work. So sufficient
(2): at most 2 non-conductive; mean at least three conductive;
could have 2 non-conductive; three conductive; no work could have 1 no-conductive; four conductive; no work could have 0 no-conductive; five conductive; work so (2) is insufficient