@AngFloz it doesn't assume that the inspectors choose a defective one just as often as they choose a working one.

if they were equally likely to choose a defective one as a working one, then they would be getting an accurate picture of the amount of defective ones that were being produced.

it assumes that they are much more likely to choose a defective one, and so they choose a lot of defective ones, even though there aren't very many defective ones overall. does that make sense?

B is a good weaken answer, but it's not the flaw in the argument.

The biggest advice that I've heard to keep yourself calm is to treat it like a practice test. That's easier when you have two or three lined up, so there's less pressure on each one. Does this have to be your last test? Is it for admissions cycle timing or are you out of attempts?

Also, I think you'll be fine if your pt score are as high as you want your test score to be. There's variance of course, but if you've done a couple official tests you're probably used to that. I think worry about how to calm yourself down can be unhelpful. We're all a little nervous on test day but you'll be fine. You know how to do the problems.