I drew my diagram like this:
Protection<--->critical thinking
I know there is no classic "if and only if" structure in the stimulus, but I reasoned that critical thinking is 1) necessary for the protection against demagogues, and also that it is 2) sufficient for the protection against demagogues. If critical thinking is the "*only adequate* protection against demagogues," why would it not be the case that, if you have critical thinking, then you've adequately protected yourself? It's not like, as in most necessary conditions, this one thing is always required but many different things could trigger the conditional. One and only one thing can trigger the conditional: critical thinking. If you have critical thinking, then you have protection against demagogues. If you have protection against demagogues, you must have critical thinking.
Then, I thought the absence of "television, telephones, and other electronic media" was required for critical thinking. Because if you have those things, then you have at least some degree of "imprecise, uncritical thinking" as the stimulus says. So taking the contrapositive, having tv/phones/media causes a lack of critical thinking. A lack of critical thinking then causes a lack of protection against demagogues. Thus, highly technological societies (those with televisions, telephones, and other electronic media) don't have critical thinking, and therefore don't have protection against demagogues. If critical thinking is the only adequate protection against demagogues, and there is no protection in these societies, therefore there must be some demagogues. So I chose (A), because I didn't think it could be possible that there would be no demagogues at all in those societies.
I diagrammed like this:
Protection against demagogues <---> critical thinking ---> NOT(television, phones, and electronic media)
Television, phones, and electronic media --> NOT(critical thinking) --> NOT(protection against demagogues)
Thus,
Technological societies ---> some demagogues
which conflicts with (A).
I'm assuming your response to me is going to be that the first sentence "Television...encourages" is not a conditional statement at all, and thus shouldn't be diagrammed like this, because "encouraging" something isn't sufficient to bring it about.
But I considered choice (D) too and rejected it...why must it be false? I thought it was perhaps possible that critical thinking was a necessary component for the "presence of an orderly system of government." If critical thinking was necessary for government, then the presence of government would provide protection against demagogues, and (D) would not be false. Does the word "mere" mean that it's not possible for an "orderly system of government" to have any other necessary components? That doesn't make sense to me; I don't know what the necessary components are, but surely there exist some (e.g., the existence of people, or whatever it means to be orderly).
Help me, please!