Question ID:PT20 S4 Q22 Passage:Wirth:  All efforts to identify a gene responsible for predisposing people to manic-depression have failed.  In fact, nearly all researchers now agree that there is no "manic-depression gene."  Therefore, if these researchers are right, any claim that some people are genetically predisposed to manic-depression is simply false.Chang:  I do not dispute your evidence, but I take issue with your conclusion.  Many of the researchers you refer to have found evidence that a set of several genes is involved and that complex interactions among these genes produce a predisposition to manic-depression. Stem:Which one of the following most accurately expresses Chang's criticism of Wirth's argument? Correct Answer Choice:AChoice A:It presupposes only one possibility where more than one exists. Choice B:It depends on separate pieces of evidence that contradict each other. Choice C:It relies on the opinion of experts in an area outside the experts' field of expertise. Choice D:It disallows in principle any evidence that would disconfirm its conclusion. Choice E:It treats something that is merely unlikely as though it were impossible.