—could you give me some advice?—sure!Don't read such books____________ you can't understand

个人觉得应该是A as
好像定语从句里面有提及到 as的用法的
定语从句中若先行词前有the same,such作修饰语,通常用as作关系代词.
He used such expressions as he could find in the texts.
They stayed for the night in the same room as they had once rented.
such…as和such..that
such…as定语从句,as在从句中可以作主语,宾语,表语；such…that引导结果状语从句,that不充当任何成分,只起到连接作用,如：
They talked in such simple language as children could understand.
They talked in such simple language that children could understand it.
如果前面是don't read the books ---- you can't understand.
就应该是 that 和which 都可以