Muhammad and Alia Are in Their Twenties

Muhammad and Alia are in their twenties. They share a household and an intimate sexual relationship with one another. They feel that their arrangement works well, since they are able to share the rent, the bills, and household responsibilities with one another. As economic conditions worsen, they see more of their friends in this type of relationship as well. Also, both of their parents are divorced and Muhammad and Alia are both concerned that this could be a path that they could follow. Muhammad and Alia's social relationship is best described as

A) cohabitation.
B) a trial marriage.
C) an extended family.
D) a conjugal family.