Why Is There So Little Social Mobility

Why is there so little social mobility?

A) Minority groups are the fastest growing groups in society and their mobility is among the lowest.
B) The tax system penalizes wealthy families and therefore they have been losing their wealth.
C) The educational system is stratified, and the tax system favors wealthy people passing their wealth to their heirs.
D) More women work outside the home.
E) Actually, there is a lot of social mobility.