Answer: All of these.
Christine fought for Raoul's life because she loved him so much. While Raoul was pleading with Christine to leave, because it didn't matter if the Phantom killed him, as long as Christine was free. Finally, Christine walked slowly to the Phantom, as her dress literally floated in the water around her, and kissed him on the lips, putting her arms on him, showing him pity. But just after the Phantom and Christine parted, the mob could be heard in the background. The Phantom freed Raoul and told the young couple to take the boat and leave, to forget all they'd seen there. After the two had left, the Phantom disappeared, leaving only his mask behind, to be found by Meg.