Which Best Describes the Impact of Genetics and Environment on a Child's

Which best describes the impact of genetics and environment on a child's IQ?

A) At age two, maternal IQ best predicts the IQ of a child; by age four, the impact of the quality of the home environment becomes as good a predictor as maternal IQ.
B) At age two, the quality of the home environment best predicts the IQ of a child; by age four, maternal IQ becomes as good a predictor as the quality of the home environment.
C) At age two, paternal IQ best predicts the IQ of a child; by age four, the impact of the quality of the home environment becomes as good a predictor as paternal IQ.
D) At age two, of the quality of the home environment best predicts the IQ of a child; by age four, paternal IQ becomes as good a predictor as the quality of the home environment.