What Is One Advantage of the Double ABCX Model Over

What is one advantage of the Double ABCX Model over Hill's earlier ABCX Model?

A) It focuses on pre-crisis areas and how a family got into the crisis.
B) It provides for normative transitions through stages of crisis.
C) It includes post-crisis areas and how a family recovers over time.
D) It accounts for differences in families-of-origin when two quite opposite people form a long-term relationship.