—I'm sorry I didn't make it to your party last night.
    —______. I know you're busy these days.
 
【正确答案】 C
【答案解析】 根据语境及答语句意可知,此处应表示“没关系”。故用That's all right。Of course“当然”,No kiding“开玩笑”,Don't mention it“别提了”,均与语境不符。