Q: What might have happened?
A: They were having in a party.
B: They were having a talk in the phone.
C: The place they were staying had the power off.
D: The man used the woman’s phone to save his life.
解析：C。A不正确，虽然有fun，但是不是在party。B不正确，这是发生在现实中的谈话。D不正确，不可以说是use the phone to save his life. 单从原文理解，至少也应该说是女方救了男方。C正确，从blackout中听出来。
Jill: Well, this has been fun.
Chandler: Yes. Yes, thanks for letting me use your phone... and for saving my life.
Jill: Well, goodbye Chandler. I had a great blackout. (she kisses him on the cheek) See ya.