What Distinction Does William Goode Draw Between a 'Family Unit

What distinction does William Goode draw between a 'family unit' and a 'family system'?

A) A family unit operates like a team, where every one works together on the same tasks. A family system operates like a factory in which every individual has their own task along the assembly line.
B) In a family unit, all the family members live together in a single home. In a family system, different family members live in different locations.
C) A family system refers to the more traditional notion of family in which the individuals are interdependent and work together as a microsocial system. A family unit refers to the modern family in which the family is a self-sustaining group.
D) Both a and b, but not c
E) None of the above