Hi @KevinRon, thanks for your post. As always, let's start with the stimulus. This one presents an argument, which is a little hidden - it's the part that starts "proponents have claimed . . ." It is this claim that is the "conclusion" - in other words, the conclusion is that there are "astronomically high odds against obtaining a match by chance alone."
What premises are given to support this conclusion? That DNA fingerprinting "uses a pattern derived from a person's genetic material to match a suspect's genetic material against that of a specimen from a crime scene" and the "assumption that there is independence between the different characteristics represented by a single pattern."
The question stem asks us to identify the answer choice that weakens ("casts the most doubt") the proponents' claim.
Notice how (E) is about something totally different than what the argument in the stimulus is about. The argument in the stimulus is about whether DNA fingerprinting reliably *identifies* a crime suspect. Answer choice (E) is about the use of DNA fingerprinting for a totally different purpose - "the investigation of certain genetic diseases." For this reason, this answer choice is irrelevant to the task at hand.
By contrast, (C) provides information that would undermine the argument in the stimulus - because if there are various subgroups in the population, and if within each such subgroup certain sets of genetic characteristics are shared, then this undermines the assumption identified in the stimulus (i.e., that each person has totally unique identifiers, or that each "single pattern" is totally unique).
Hope this helps. Please let us know if you have any additional questions.
