Question ID:PT37 S2 Q24 Passage:Roxanne:  To protect declining elephant herds from poachers seeking to obtain ivory, people concerned about such endangered species should buy no new ivory. The new ivory and old ivory markets are entirely independent, however, so purchasing antique ivory provides no incentive to poachers to obtain more new ivory. Therefore, only antique ivory‚ that which is at least 75 years old‚ can be bought in good conscience.Salvador:  Since current demand for antique ivory exceeds the supply, many people who are unconcerned about endangered species but would prefer to buy antique ivory are buying new ivory instead.  People sharing your concern about endangered species, therefore, should refrain from buying any ivory at all‚ thereby ensuring that demand for new ivory will drop. Stem:Which one of the following principles, if established, would most help to justify Salvador's position? Correct Answer Choice:EChoice A:People concerned about endangered species should disseminate knowledge concerning potential threats to those species in order to convince others to protect the species. Choice B:People concerned about endangered species should refrain from buying any products whose purchase could result in harm to those species, but only if acceptable substitutes for those products are available. Choice C:People concerned about endangered species should refrain from the purchase of all manufactured objects produced from those species, except for those objects already in existence at the time the species became endangered. Choice D:People concerned about endangered species should refrain from participating in trade in products produced from those species, but only if workers engaged in that trade also agree to such restraint. Choice E:People concerned about endangered species should act in ways that there is reason to believe will help reduce the undesirable results of the actions performed by people who do not share that concern.