Piaget Believed That the Exact Timing of a Stage Reflects

Piaget believed that the exact timing of a stage reflects an interaction between the infant's ________ and __________.

A) level of physical maturation; the experience of the environment
B) level of physical maturation; the genetic predisposition of the child
C) level of cognitive development; the environment in which the child is raised
D) level of physical maturation; cognitive development of the child