问题详情

Which of the following statements about salt is Not True？
A．For many years people have been unaware of the many problems of salt including its corrosive effects.
B．Salt is the cheapest among its many alternatives with its purchase price of $ 25 a ton.
C．The national bill of salt may reach as high as $ 5 billion a year.
D．The economic cost of salt is still lower than the cost of CMA.请帮忙给出正确答案和分析，谢谢！