作者：英吉
A drug that is highly effective in treating many types of infection can, at present, be obtained only from the bark of the ibora, a tree that is quite rare in the wild. It takes the bark of 5,000 trees to make one kilogram of the drug. It follows, therefore, that continued production of the drug must inevitably lead to the ibora's extinction.
Which of the following, if true, most seriously weakens the argument above?
(A) The drug made from ibora bark is dispensed to doctors from a central authority.
(B) The drug made from ibora bark is expensive to produce.
(C) The leaves of the ibora are used in a number of medical products.
(D) The ibora can be propagated from cuttings and grown under cultivation.
(E) The ibora generally grows in largely inaccessible places.
题目分析：A说这种药从当局分发给医生，没说，杀。B说这种药生产费用很高，谈的是生产费用问题，没说。C说这种树的叶子能生产各种医疗产品，也没说，杀。D说这种树能人工培育，原文说这种树野外有，这个选项说除了野外还有别的地方可以有这种树，显然是驳斥，留着。E说这种树通常·在一些偏僻的地方才能生长，即便有关系也不能驳斥，杀。
