A Jean Piaget and Lev Vygotsky would explain this as egocentric nature of the child's thoughts.
B Jean Piaget would explain this as egocentric speech, while Lev Vygotsky would explain this as the child's attempt to regulate her actions through private speech.
C Jean Piaget would explain this as social interaction, while Lev Vygotsky would explain this as an exploration.
D Jean Piaget and Lev Vygotsky would explain this as the child's attempt to imitate her mother.