Answer:
C. Making major changes to the atmosphere can be a costly process.
Explanation:
The statement that provides best argument against is option C, because making changes to the atmosphere can be a high cost process, economically or even naturally. The principal fact here is that we don't know what will exactly happen if we tried to apply some things to the atmosphere. For example, cloud bombing, it's not a secret that this action to make rain more often, brought several disasters in many countries, because it was develop without knowing the outcome.
On the other hand, let's say that we know the effects after altering atmosphere to positive outcomes. Probably the cost of the process itself would be huge, while other options could be available.
