Question ID:PT40 S3 Q5 Passage:Sickles found at one archaeological site had scratched blades, but those found at a second site did not.  Since sickle blades always become scratched whenever they are used to harvest grain, this evidence shows that the sickles found at the first site were used to harvest grain, but the sickles found at the second site were not. Stem:Which one of the following, if shown to be a realistic possibility, would undermine the argument? Correct Answer Choice:BChoice A:Some sickles that have not yet been found at the first site do not have scratched blades. Choice B:The scratches on the blades of the sickles found at the first site resulted from something other than harvesting grain. Choice C:Sickles at both sites had ritual uses whether or not those sickles were used to harvest grain. Choice D:At the second site tools other than sickles were used to harvest grain. Choice E:The sickles found at the first site were made by the same people who made the sickles found at the second site.