问题详情

Which of the following is the cause for America"s e-commerce giants moving into China and the rest of Asia？
A．eBay is posting record profits.
B．Amazon is in the black for the first time in its eight-year history.
C．U.S. growth rates are starting to slow.
D．European e-commerce is too matur请帮忙给出正确答案和分析，谢谢！