I'm confused --- "That's valid. In fact, that's the contrapositive argument form. The only problem is that you made up your own premise B → A. The actual premise is A → B. You confused sufficiency for necessity."

If we're following the contrapositve argument form, how then did we confuse the sufficiency for necessity?

Seems to me that the reviewing the question first would help determine which sufficient conditions should be kept in the rule v. the domain. Is that an accurate game plan?

That "no" threw me for a loop! Will definitely be more on the lookout for negatives now :)

Assumption. I have to assume less in the Disney, followed by tiger, and then cat.