问题详情

According to the passage, one of the causes for the difficulties of American higher education is that ______.
A．the government has stopped giving public institutions as much financial support as it used to
B．America has always been encouraging young people to go to college
C．many public institutions have replaced private ones
D．the government only finances such researches as that of placing man on the moon请帮忙给出正确答案和分析，谢谢！