Question ID:PT50 S4 Q18 Passage:It was once thought that pesticide TSX-400 was extremely harmful to the environment but that pesticides Envirochem and Zanar were environmentally harmless. TSX-400 was banned; Envirochem and Zanar were not. However, according to recent studies, Envirochem and Zanar each cause greater environmental harm than does TSX-400. If these studies are accurate, then either Envirochem and Zanar should be banned or TSX-400 should be legalized. Stem:Which one of the following principles, if valid, most helps to justify the argumentation? Correct Answer Choice:DChoice A:Two pesticides should not both be legal if one is measurably more harmful to the environment than the other is. Choice B:Two pesticides should both be legal only if neither is harmful to the environment. Choice C:Two pesticides should both be illegal only if both are harmful to the environment. Choice D:One pesticide should be legal and another illegal only if the former is less harmful to the environment than is the latter. Choice E:One pesticide should be legal and another illegal if the former is harmless to the environment and the latter is harmful to it.