After the Civil War, ______ became a strong trend in American ec

After the Civil War, ______ became a strong trend in American economy.
A、disappearance of private business
B、increase in capital investment
C、monopoly by big business
D、nationalization of enterprises
【正确答案】：C
【题目解析】：内战后，大企业垄断成为美国经济的一个强劲趋势。