问题详情

John Doerr called the boom in the 1990s the "largest single legal creation of wealth" because
A．corporate profits were mostly gained by lower interest rates.
B．productivity rose at a 2.20% annual rate over this 10-year period.
C．consumer spending stayed so strong even in the recession.
D．many workers were qualified for the sorts of jobs in production.请帮忙给出正确答案和分析，谢谢！