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

正确答案是B