请问一道英语选择题

题目

请问一道英语选择题
（ ）Mrs Brown with her daughter ______back to London for a holiday.
A.have gone B.has been C.has gone D.have been
个人觉得选C,意为回伦敦度假,但是答案为B,想请教英语高手这个答案哪一个更好.

答案

（ ）Mrs Brown with her daughter ______back to London for a holiday.
A.have gone B.has been C.has gone D.have been
个人觉得选C,意为回伦敦度假,但是答案为B,想请教英语高手这个答案哪一个更好.
答：C
译：布朗夫人与其女儿已经回伦敦度假去了.
析：此题考主谓一致,真主为Mrs.Brown,排除AD
如没有关键词back,和for a holiday,则BC皆可：
B.Mrs Brown with her daughter has been to London .母女俩去过伦敦.（现不在伦敦）
C.Mrs Brown with her daughter has gone to London .母女俩已经去了伦敦.（现不在本地）
加了两个关键词后,则B不如C佳.但B免强能说得过去.
B.Mrs Brown with her daughter has been back to London for a holiday.母女俩已经回伦敦度假过了.（现不在伦敦）这个back就不太好说了.因为她们又回来了.到底去哪里算back?