are A and B wrong because they are putting the conclusion in the place of a premise in the answer choice? For an AC to be correct, does it need to follow the format of "presumes that PREMISE"

but couldn't you also explain answer choice C using CNN?

Here's another tip. Choose the ONLY answer that does not bring in any sort of outside information. If an answer choice gives us information that wasn't given to us in the stimulus, why would you choose it? You really have to stick to just using the stimulus for everything you know.

what does it mean by "Affirming or satisfying the necessary condition yields no information about the sufficient condition"

Neither of the two populations of sockeyes having bred with the native salmon (A) increases the likelihood that the sockeyes' having adapted genetically to each of their habitats is the reason for them differing genetically. A is ruling out an alternative explanation.

if we understand these already, can we just skip over them? I feel there's no purpose in adding complexity or more context to something we can easily understand on it's own.

is getting the contrapositive even necessary if we already understand the originally intended, english meanining? What's the point in adding an extra step besides seeing another way to interpret the sentence

was this part only super relevant for logic games?? I know it still is important but it seems tailored towards that.

Notice why A and E are wrong. They each take information from the environmentalists beliefs and present it as a fact. DO NOT fall for these trap AC's. One cannot take someone's belief and write it off as a real world fact, which is what A and E are doing.