Correct Response: C. Fossilization of interlanguage structures is a phenomenon whereby a language learner makes progress in certain areas of language learning but fossilizes, or "gets stuck," in other areas, thus continuing to make certain errors in the target language. The scenario given represents a typical example of fossilization. A is incorrect because the student is described as being "at an advanced stage of English language acquisition," and therefore does not display a delay in internalizing grammar rules. B is incorrect because positive transfer from the first language to the target language means that the first language has similar linguistic elements to that of the target language. This would promote rather than inhibit language learning. D is incorrect because code-switching means that the student alternates between the first language and target language, which is not evident in the scenario provided.