B
After temperature reaches certain treshold the difference between density of liquid and gas state disappears, and it is impossible to liquify the substance.
Answer:what do u mean tho
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The critical temperature of a pure substance is the temperature above which the liquid phase cannot exist, even under high pressure. Therefore, the correct answer is B. This temperature marks the threshold at which the gas phase becomes distinct from the liquid phase, leading to a supercritical state.
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