Concept:Vygotsky’s sociocultural theory stresses that cognitive development is deeply rooted in social interaction and language.Explanation:Vygotsky argued that cognition does not develop in isolation. It is shaped by social exchanges with more knowledgeable people, such as parents and teachers. Language plays a key role because children first use social speech to communicate, then internalize it as inner speech. This process helps them think, solve problems, and regulate behavior. The Zone of Proximal Development (ZPD) further highlights that learning happens best when a child gets guided help from others. Therefore, for Vygotsky, cognition is fundamentally a social and language-based process.Answer:D. social and language-based