What is the primary difference between Piaget's and Vygotsky's theory?
A) Piaget talked about the importance of cognitive development and Vygotsky did not
B) Piaget emphasized stages of development, Vygotsky emphasized cultural influence
C) Piaget focused on natural progression, Vygotsky on social interaction
D) Vygotsky introduced the zone of proximal development, Piaget did not