求问大神一题，感激涕零！

小鱼u

The standard framework of cap and trade is fundamentally conservative, in which a central body generally establishes a limit on the total amount of pollution that can be produced, allocates a certain number of permits, and then allows market forces to dictate the price a company must pay to pollute.


A. standard framework of cap and trade is fundamentally conservative, in which a central body generally establishes a limit on the total amount of pollution that can be produced, allocates a certain number of permits, and then allows market forces to dictate the price a company must pay to pollute

B. standard framework of cap and trade, a central body generally establishes a limit on the total amount of pollution that can be produced, allocates a certain number of permits, and then allows market forces to dictate the price that companies must pay to pollute, is fundamentally conservative

C. standard framework of cap and trade—a central body generally establishes a limit on the total amount of pollution that can be produced, allocates a certain number of permits, and then allows market forces to dictate the price a company must pay to pollute—is, fundamentally, a conservative one

D. fundamentally conservative standard framework of cap and trade is: a central body generally establishes a limit on the total amount of pollution that can be produced, allocates a certain number of permits, and then allows market forces to dictate the price that a company must pay to pollute

E. fundamentally conservative standard framework of cap and trade, in which a central body generally establishes a limit on the total amount of pollution that can be produced, allocates a certain number of permits, and then allows market forces to dictate the price that companies must pay to pollute


答案选C
求问BC之间怎样选择？是因为dash和comma之间的区别吗？谢谢！