Question ID:PT91 S2 Q24 Passage:Scientist:  Some consumer groups claim that the economic benefits of genetically engineered foodstuffs may be offset by hidden health risks to humans. However, the risk is minimal. In most cases of deliberate alteration of a plant's genetic structure only a single gene in about 750,000 has been changed. Since the change in the organism's genetic structure is so slight, it cannot have effects significant enough to be worrisome.  Stem:Which one of the following, if true, most weakens the scientist's argument? Correct Answer Choice:DChoice A:The genetically engineered plants that have been developed so far have few advantages over plants that are not genetically engineered. Choice B:Whatever health risks there are in food from genetically altered plants may be somewhat reduced by other factors such as enrichment of the plants' vitamin and mineral content. Choice C:Scientists have yet to determine, for each characteristic of some plants and animals used for food, the precise location of the genes that determine that characteristic.  Choice D:There are plants that are known to be toxic to some animals and whose toxicity is known to be affected by the alteration of a single gene. Choice E:Research has shown that those consumers who are most strongly opposed to genetically altered foods tend to be ill-informed on the issue.