Could you tell me which department Miss Helen Walt is in and her phone number?

Could you tell me which department Miss Helen Walt is in, and her phone number？

A、请问海伦·瓦尔特小姐是哪个部门的，她的电话号码是多少？

B、请问海伦·瓦尔特小姐现在在哪个部门，我怎样找到她的电话号码？

C、请问海伦·瓦尔特小姐是哪个商场的，我怎样找到她？