If a System Is "Closed," It Means That

If a system is "closed," it means that:

A) you can't get out
B) wastes are injected from outside and degrade environmental quality
C) An Inconvenient Truth is the only movie you can watch
D) growth is impossible
E) wastes must be recycled in the long run or environmental quality will degrade
F) the price system cannot be used to manage growth and the environment