The Opportunity Cost of Slowing Global Warming by Reducing Carbon

The opportunity cost of slowing global warming by reducing carbon dioxide emissions is

A) extremely high because policies that would significantly reduce emissions will adversely affect economic growth.
B) insignificant compared to the probable impact of warming from those emissions.
C) irrelevant because each aspect of the environment is important enough to justify full protection from environmental change, at whatever cost is necessary.
D) zero because fuel cost savings alone will offset all opportunity costs.