Why not buy ______for your brother for his birthday?

--Why not buy ______for your brother for his birthday? --Good idea.
A. something special       B.anything special        
C.special something        D.special anything
正确答案：A
贝贝英语网解析：

这个题考的复合不定代词的用法。复合不定代词+形容词。这个位置关系必须熟记。

所以能排除C和D选项。

why not+动词原形+其它？这个句型是用来表建议的，那么表建议的问句只能用something，不用anything,所以选A。