结合具体实例，综合分析学前儿童问题行为产生的主要原因。

A. only indulge in empty talks.
B. advocate fairer opportunities.
C. boost the equality of outcomes.
D. ignore the real need of the poor.

A. the richest receive income four times more than the poorest.
Britain is an OECD member with the highest rate of inequality.
C. wealth distribution is more unequal than income distribution.
D. most gaps between social groups have disappeared over time.