Question ID:PT48 S4 Q8 Passage:This stamp is probably highly valuable, since it exhibits a printing error. The most important factors in determining a stamp's value, assuming it is in good condition, are its rarity and age. This is clearly a fine specimen, and it is quite old as well. Stem:The conclusion is properly inferred if which one of the following is assumed? Correct Answer Choice:BChoice A:The older a stamp is, the more valuable it is. Choice B:Printing errors are always confined to a few individual stamps. Choice C:Most stamps with printing errors are already in the hands of collectors. Choice D:Rarity and age are of equal importance to a stamp's value. Choice E:Even old and rare stamps are usually not valuable if they are in poor condition.