参考答案

正确答案：B
解析：细节题。短文开头提到邮票印刷错误会使之升值，随后举了一个例子，最后指出“Be cause of the Two Penny Blue's rareness and age，it has been so expensive that collectors have paid as much as $16，800 for it”，也就是说升值的关键还是邮票的稀有与年代久远。选项B的rare与old对应原文的rareness与age。选项A是强干扰项，对邮票升值的原因理解过于片面。