参考答案：A

解析：[听力原文]
F: My father often put Christmas presents in my stockings, but last night my mother did that.
M: Oh, I know your mother was really Father Christmas on Christmas Eve.

[详细解答] 根据对话内容，女：“我父亲经常把圣诞礼物放在我的袜子里，但昨晚是母亲放的。”男：“我知道你母亲是真正的平安夜的圣诞老人。”