Concept:Vygotsky's sociocultural theory says that thinking develops from social interactions and is built together with others.Explanation:Vygotsky believed that thinking is not a private event. It grows through shared activities where a child and a more skilled person work together. Language is a key tool in this process. During these interactions, the child learns to use language to guide their own thinking. This co-construction of knowledge makes thinking a social activity. Option A matches this idea. Option B is wrong because context is essential. Option C describes behaviorism, not Vygotsky. Option D is false because Vygotsky argued that thought and language are closely linked.Answer:A. is co-constructed during shared activities between the child and another person.