Which of the Following Demonstrates One of the Core Questions

Which of the following demonstrates one of the core questions generated by the Genain quadruplets?

A) Is Bruce an anxious child because his parents are overprotective,or did Bruce's frail nature cause his parents to be overprotective?
B) Is Donna angry most of the time because her parents were always at work?
C) Is Teresa depressed because her sister gets more attention or because she doesn't like school?
D) Is Ronald overweight because he overeats,or is it because he does not like to go outside?