Which of the Following Statements About Recent Research in Developmental

Which of the following statements about recent research in developmental psychology is true?

A) Recent research has settled the controversy of the influences of nature and nurture.
B) Recent research has questioned some of Piaget's theories, such as object permanence.
C) Recent research has conclusively authenticated virtually all of Freud's psychosexual theories.
D) Recent research has created suspicion that Piaget's original studies may have been falsified.