A "Conjugal Unit" and a "Nuclear Family" Are Different in That

A "conjugal unit" and a "nuclear family" are different in that:

A) A nuclear family can contain a conjugal unit.
B) A conjugal unit consists just of the husband-wife pair, while a nuclear family can include children.
C) A conjugal unit can include aunts and uncles, but a nuclear family cannot.
D) Both (a) and (b) above.
E) None of the above.