Anna and Isabelle Were Each Raised in Isolation, but Anna

Anna and Isabelle were each raised in isolation, but Anna subsequently was more successfully socialized. The difference in outcome can be explained by the fact that

A) Anna was much younger than Isabelle when she was rescued.
B) Anna had been fed more nutritious foods.
C) Anna had been allowed brief visits with outsiders.
D) Anna's mother was present during her early years.
E) all of these