Happy to help. Let's take a look at (B). As the question stem notes, we're looking to pick the answer that most logically completes the argument.
(B) says, "cannot survive unless many of its citizens have some beliefs that are literally false"
While it's true that (B) appears to be an extreme answer choice, it's actually proven by the premises of the argument. A nation's survival is dependent upon its citizens believing that the nation has moral rights and responsibilities, and—as the stimulus notes—these are false beliefs. Therefore, (B) is the correct answer choice.
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