all is negated to some, some is negated to either all or none, and most is negated to 50% or less

I think the contrapositive is actually what helped me with this a lot. Sometimes I would start with that and work backwards to figure out the logic of what the sentence was saying. Maybe won't work with more complex things, but it helped me figure out which one was sufficient and which one was necessary.

I feel like b was a trap answer for me. I assumed the rest of the context was all the conclusion, but that's not what the argument was saying. The argument is saying, so these critiques you're making? That's too fuzzy bro. The only one that does that is (A). (B) is just a repeat of what critics say. That is just context without the real conclusion, it's half of the real picture. When we take that with the idea of it being too fuzzy, that's the conclusion.

Counterexample was a word I didn't know. The definition that came up: an example that shows it contradicts an idea or theory. So it's meant to disprove something or show something is wrong. So in the video, when JY says Cats are nice, and I say wait no, you're wrong, and point out that Garfield and Jerry mean-- that's a counterexample. Which is why B is wrong. The author doesn't say that the conclusion was wrong, in fact they say the conclusion might be right. That's not a counterexample. That's just being nice and curious, looking for alternative explanations.