Question

…The achievement gap between black and white

Answer 1

I think it would be likely to assume that the racial makeup of those schools did not change much and that the first school is predominantly black, and the second predominantly white. And what we see is a better performance in the first of the two schools.

This is likely a consequence of the racial segregation and the discrimination of the non-white population in South Africa till 1994, so the correct answer is (1) inequalities existing between the races under apartheid