A：已经去图书馆了（现在已经回来了） B：已经去了（去过还没回来）C：表示在某个地方从过去一直延续到现在
D：是错的 所以答案是（B）
has been to 表示去过某个地方(现在已经回来了)
eg.I've been to Beijing twice.
has gone to 表示去了某个地方(但还没有回来)
eg.Sorry.He isn't at home.He has gone to Beijing.
has been in 指的是从过去一直到现在都在某个地方.
eg.I have been in Beijing for 10 years.
如果没弄懂可以单独找我询问.