Answer:
Country B, where education is well-developed and social stratification is lacking.
Explanation:
As in country B people are well educated they understand the concept of advancement and growth. As there is no social stratification people are not biased or do not perform racism.
Accordingly, the people in that country will contribute actively and participate actively in the process of production. As people are well versed with education, they will readily accept the change of growth.
It is expected from them to perform better than any other country, as because of positive standards of the country.