Berko's Classic Study in Which She Showed Children a Nonsense

Berko's classic study in which she showed children a nonsense object labeled a "wug" and then presented the child with a picture of two of these objects to see how the child would supply the plural form of "wug" demonstrated that preschool

A) children's use of grammatical morphemes is based on rules.
B) children do not use inflection.
C) children's language is not based on memory for individual words.
D) children acquire a rule for using "un + verb" to reverse or stop the action of a verb.