@FrancisZaklukiewicz Yes, it's a very popular approach for all question types. I find it helpful because I know what to look for in the stimulus before reading it, relevant facts and parts of the stimulus stand out if you know what to look for ahead of time. That way you're less likely to have to read the stimulus a second time.

Of course, some people prefer reading the stimulus first so try a couple of drills with each approach and see what you like better.

I've had o watch the video several times to understand the explanation for choice A but here's what I think a lot of us are missing and why we're confused. We're supposed to account for the correlation between higher amounts of dietary iron and development of parkinsons, not account for the relationship between genetics and parkinsons.

An alternate explanation to "High dietary iron causes parkinsons" is "People who have a parkinsons predisposition happen to eat more iron", the iron could be correlated to parkinsons only because it's piggybacking off of the genetic predisposition.

Answer choice A eliminates that explanation because it tells us that people who are more likely to develop parkinsons DON'T eat extra iron. The iron/parkinsons correlation is independent of the genetics/parkinsons correlation.

Therefore, we can eliminate the alternate explanation of them being connected. This strengthens the journalists reasoning because there are fewer possible explanations for the phenomenon available now, so the journalist's hypothesis is a bit more likely overall.

That's the best way I can think to articulate it, I hope it helps someone.