Exchange Errors, in Which Two Linguistic Units Are Substituted, Occur

Exchange errors, in which two linguistic units are substituted, occur

A) in feature comparison theories, but are not consistent with hierarchical networks theories.
B) so infrequently that their absence is strong evidence for a deep structure of language.
C) at the same level in the hierarchy, indicating that language is hierarchically organized.
D) at different levels in the hierarchy indicating that language is sequentially organized.