Q: What are they talking about?

A: They are expressing anger to someone.

B: They are expressing appreciation to someone.

C: They are asking someone to be different.

D: They are leaving because the coma makes the other one different.

解析：A

整段对话的意思是，我们为你付出了那么多，你却只说了一句回见，或许是你之前昏迷，才让我们觉得你和其他人不一样而已。因此整个对话是这两位在向另外一位表达愤怒。A正确，B表达感谢不正确；CD不正确。

Monica: This is so typical. Y' know, we give, and we give, and we give. And then- we just get nothing back! And then one day, y' know, it's just, you wake up, and "See you around!" Let's go, Phoebe.
Phoebe: y' know what? We thought you were different. But I guess it was just the coma.

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