The passage talks about how globalisation results in people adopting a common language (lingua franca), thereby abandoning their native languages. It also emphasises that losing a language means more than losing words or communication-it involves losing a way of thinking.
Of the choices given, the best statement to fit here is "Languages exist not only for the purposes of practical communication; they convey a linguistic community's entire mindset and its culture" (Option C) because it directly supports the idea that language loss impacts culture and thought, reinforcing the sentence that follows about the death of a way of thinking.
The other options, while related to language, do not directly explain the deeper significance of language loss. Option A discusses revival movements, Option B talks about endangered languages' status, and Option D focuses on language evolution over time. Option C clearly ties language to mindset and culture, fitting the paragraph's argument perfectly.
The correct answer is therefore Option C.