Which of the Following Statements Best Describes Cohabitation

Which of the following statements best describes cohabitation?

A) It is an arrangement in which two unrelated people are not married but live together and are in a sexual relationship.
B) It is a marital union of a man and a woman who decide to be childless by choice.
C) It is an arrangement in which a married couple and their respective families stay together in the same house.
D) It is a relationship where a man or woman has more than one sexual partner and all of them live in the same house.
E) It is an arrangement in which two related people live together.