Which Statement About the Association Between the Intellectual Quality of the Family

Which statement about the association between the intellectual quality of the family environment and children's IQ scores is NOT true?

A) There is a confirmed causal relation between the intellectual quality of the family environment and IQ score.
B) IQ score is positively correlated with the intellectual quality of the family environment throughout childhood.
C) The intellectual quality of the family environment at an early age is associated with IQ score at a later age.
D) If the intellectual quality of the family environment decreases, IQ score tends to decrease as well.