What Was Piaget's Explanation as to Why Preschool-Age Children in the Preoperational

What was Piaget's explanation as to why preschool-age children in the preoperational stage make errors on tasks requiring conservation?

A) Preschool-age children's neural-visual network is not fully matured.
B) Ppreschool-age children have not lived long enough and accrued enough experience to know the difference between quantities.
C) Preschool-age children's tendency toward centration prevents them from focusing on other relevant features of a situation.
D) Preschool-age children have not yet developed numerical understanding; therefore, different amounts are meaningless.