-Do you have anything----?I will be staying in the U.S for a

A to buy 正确,因为anything是不定代词,后面的不定式修饰它.即不定代词的定语要后置.如
Would you like something to drink?Yes,a little juice,更上一层楼!
不明白的再问哟,请及时采纳,多谢
再问： 答案是B····还有为什么不能是C？不是有have sth done的结构么
再答： 有have sth done的结构，但此结构是“表被动关系”如I had my hair cut last week,上周我理发了。