I hate to say it but I believe B is a bit confusing and might be a possible answer. My logic behind this is that the stimulus states the device being installed ramped up in the past two years, but was being installed before that time too. If the information going missing only became common place in the past two years, then how can one say it was 100% the device causing the missing info?

B can weaken the argument by making that claim. At least thats how I see it, but I can see how D does this better.

Literally got it wrong twice, once before and once in BR. Then I reread the question and noticed I forgot the word EXCEPT. Literally facepalmed.

2/3 then 3/3. I see why the polls one is a bit tricky. Using the contrapositive shows why some of the answers are wrong, and it takes a bit of brain wrangling to work around the Why part.

Hmm so whenever I do the contrapositive negation I want to flip the non-contrapositive.

Ex: All marines eat yellow crayola crayons

Marines --> eat yellow cc

/eat yellow cc --> /Marine

At least I believe this is right, really bad example but its good to see I need to flip them.

Got a 3/5 on actual, and then 3/5 on blind review. Found out that theres a pattern or way to answer assumption questions compared to normal ones from the blind review though, so hoping I won't make this mistake again!