What Factors Determine How the Importance of Family Functions Varies

What factors determine how the importance of family functions varies cross-culturally?

A) The size of the population is the most important factor in determining the relative importance of family functions.
B) Factors related to provision of services by other means and the availability of contraception shape how important different family functions are cross-culturally.
C) It is not possible to identify any factors relating to the relative importance of the functions of family.
D) None of the above; there is no variation in the importance of family functions cross-culturally.