Step 1: Understanding child language acquisition
Children acquire language naturally and creatively, not simply by imitating their parents. They generate new utterances and apply grammatical rules, sometimes overgeneralizing them. This shows their productivity and creativity in language use.
Step 2: Examining the options
- (A) This is correct. Children often produce errors like \emph{goed} (for went) or \emph{foots} (for feet), which are not present in adult speech. These are called overgeneralization errors, and they demonstrate that children are applying rules productively and creatively.
- (B) This is incorrect because children do not replicate parental errors (adults usually provide grammatically correct input). Their errors are new creations, not copied.
- (C) While children may sometimes omit inflections (e.g., \emph{He go} instead of \emph{He goes}), this does not demonstrate creativity and productivity—it reflects an early developmental stage.
- (D) Reproducing nursery rhymes or songs is an act of imitation, not creativity. It does not show productive use of grammar.
Step 3: Conclusion
Option (A) best captures the idea that child language acquisition is a creative process where children generate new grammatical forms, even if incorrect, showing productivity beyond imitation.
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\boxed{\text{Correct Answer: (A)}}
\]