PT 40 S3 Q5

Sickles found at one archaeological site had scratched blades, but those ... ...

Which one of the following, if shown to be a realistic possibility, would undermine the argument?
(A) Some sickles that have not yet been found at the first site do not have scratched blades.
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Practice Set: "Weaker" Questions, Set 3 - Difficult/Uncommon Mix (25Q)