-I can't find Ms.Miller.Where did u meet her this morning?

where 吧~~

I can't find Ms.Miller.Where did u meet her this morning?
-It was in the hotel( WHERE )she was staying

2 which

前面已经有了in the hotel 故不需要用in which连接 其他的不适合
又因为此句不能为强调句 故可排除that

that, 典型的强调句型

选4
因为in the hotel是主句的补语，此句为补语前置

That,这是强调句，从句子可以还原为He was staying in the hotel看出