What was the key difference between economic & social mobility between poor whites & african americans?

The major difference between economic and social mobility between  poor whites and african americans were:

Explanation:

Even though the income for both african americans and poor whites increased there was a big gap between the pays they got.Children's of the white people were highly likely to move up in their life in comparison to  african americans.Children's of the white people were highly likely to surpass their parents income compared to african americans at the same point in life.White people were preferred for any work compared to african american regardless of their skills.

The third one would be the answer