According to the passage, which of the following is TRUE?
A.Poor pre-school kids have a larger vocabulary than rich kids.
B.President Obama believes that early education can solve all economic and social problems.
C.Rich pre-school kids have a richer vocabulary than poor kids.
D.President Obama"s education secretary thinks it is morally wrong to let kids start kindergarten early.
请帮忙给出正确答案和分析,谢谢!