The idiom tit for tat is not to be turned into tat for tit. This shows that（）.

The idiom tit for tat is not to be turned into tat for tit. This shows that（）.
A、many idioms are grammatically unanalysable
B、the word order ofidioms cannot be inverted or changed
C、the meaning of an idiom is to a large extent unchangeable
D、the constituents ofan idiom cannot be deleted or added to
正确答案：B