In the Context of Recent Trends, Identify the Reason That

In the context of recent trends, identify the reason that has made cohabitation widespread and accepted in the United States.

A) Young adults defer marriage longer, and cohabitation is seen as a viable living arrangement.
B) More gay and lesbian couples are "coming out" and living together.
C) Cohabitators disregard sexual exclusivity with partners and redefine fidelity as faithfulness to all sexual partners involved in the relationship.
D) Young adults are able to maintain intimate relationships with more than one sexual partner in a cohabitation.