Question ID:PT92 S1 Q17 Passage:For several years the Technology Institute has used a new experimental curriculum in its plumbing program. A survey last year found that only one-third of the Institute's plumbing graduates‚ well below the national average‚ were able to pass the plumber's certification test. This shows that the new curriculum has lowered the quality of plumbing instruction. Stem:The reasoning in the argument is most vulnerable to criticism on the grounds that the argument Correct Answer Choice:CChoice A:treats a phenomenon as an effect of an observed change in the face of evidence indicating that it may be the cause of that change Choice B:uses a lack of evidence that the quality of the Institute's plumbing instruction has increased as though it were conclusive evidence that it has decreased Choice C:concludes that something has diminished in quality from evidence indicating that it is of below-average quality Choice D:uses a national average as a standard without specifying what that national average is Choice E:confuses a factor's presence being required to produce a phenomenon with the factor's presence being sufficient in itself to produce that phenomenon