What Has Been Demonstrated in More Modern Research Examining Piaget's

What has been demonstrated in more modern research examining Piaget's cognitive stages

A)  Children outside of Western cultures do not show evidence of progress through Piaget's stages. 
B)  Most children do not pass through the stages in the order that Piaget suggested. 
C)  Children likely develop some cognitive skills much earlier than Piaget estimated. 
D)  There is no evidence that children can be in more than one stage at a time.