All of the Following Are True of Research into the Effects

All of the following are true of research into the effects of early environmental enrichment, except one? Which is NOT true of research into enrichment effects?

A) Classic studies showed that rats reared in enriched environments scored very high on a rat I.Q. test, regardless of their genetic endowment.
B) CT, PET, and MRI research has shown that children reared in enriched environments have larger brains and more nerve cells than children reared in other environments.
C) Craig Ramey and colleagues have shown that children for whom the genetic prediction would be low intelligence have shown sustained high intelligence following exposure to early enrichment.