Professor Smith published a paper arguing that a chemical found in minute quantities in most drinking water had an adverse effect on the human nervous system. Existing scientific theory held that no such effect was possible because there was no neural mechanism for bringing it about. Several papers by well-known scientists in the field followed, unanimously purporting to prove Professor Smith wrong. This clearly shows that the scientific establishment was threatened by Professor Smith' s work and conspired to discredit it. Which one of the following is the central flaw in the argument given by the author of the passage? ['The author fails to mention whether or not Professor Smith knew that the existence of the alleged new effect was incompatible with established scientific theory.', "The author passes over the possibility that Professor Smith had much to gain should Professor Smith's discovery have found general acceptance.", 'The author fails to show why the other scientists could not have been presenting evidence in order to establish the truth of the matter.', "The author fails to indicate what, if any, effect the publication of Professor Smith's paper had on the public's confidence in the safety of most drinking water."]