Final answer:
Chomsky's term for a child's innate set of mental structures that aids in language learning is called the Language Acquisition Device (LAD).
Step-by-step explanation:
Noam Chomsky, in his critique of B. F. Skinner's behaviorist explanation of language learning, proposed that humans are born with an innate biological mechanism that aids in language acquisition. This mechanism is known as the Language Acquisition Device (LAD). Chomsky's theory emphasizes that while environmental factors (nurture) and feedback such as parental approval play a role in language learning, the innate capacity (nature) each child possesses to learn language is critical. Researchers recognize that language acquisition is a complex process influenced by both inherited biological predispositions and interactive linguistic environments.