Mary is___only girl who has been to Amexian in our company A:a B:the C:an D:\

Mary is___only girl who has been to Amexian in our company A:a B:the C:an D:\
Mary is___only girl who has been to Amexian in our company A:a B:the C:an D:\

Mary is___only girl who has been to Amexian in our company A:a B:the C:an D:\
B
Mary is the only girl who has been to Amexian in our company.
Mary是我们公司唯一一个去Amexian（话说这里应该是American吧?）的女孩.

b

THE
有only的嘛。

B表强调