What Is One of the Main Findings of the Up

What is one of the main findings of the Up series?

A) Biology is a stronger predictor of social outcomes than are social factors.
B) By age 7, children have already been socialized into their economic class.
C) British society, like American society, is highly fluid, so people are able to move across class lines fairly easily.
D) Ending childhood poverty is possible if a society commits to it.