I'll give you a question, please answer with step-by-step reasoning process.
Of the below sentences, which one does *not* make sense?\nOptions:\n- Sentence A: "Dinosaurs are extinct species."\n- Sentence B: "Dinosaurs are on the brink of extinction."\n

Sentence B
Dinosaurs have already been extinct millions of years ago.

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So, the final answer is Sentence B