Studies on Early Childhood Prorams for Disadvantaged Children Have Demonstrated

Studies on early childhood prorams for disadvantaged children have demonstrated that

A) the children in these programs had IQ gains that were maintained for seven years.
B) the children in these programs had initial IQ gains, which were lost after five years.
C) the children in these programs showed no IQ gains as compared to the control group.
D) these programs could not prevent the children from falling behind in school.