Why do CFC compounds reach the stratosphere despite being stable?

The correct choice highlights that CFC (chlorofluorocarbon) compounds have a long atmospheric lifetime, which allows them to gradually rise to the stratosphere where they can break down and release chlorine atoms that deplete ozone.

CFCs are stable at lower altitudes; however, their longevity means they do not easily degrade in the lower atmosphere. Over time, these stable compounds can slowly ascend through the troposphere and reach the stratosphere, where they are subjected to higher energy ultraviolet (UV) radiation. This UV radiation initiates a breakdown of the CFC molecules, releasing chlorine radicals that contribute to ozone layer depletion.

The other options touch on various physical properties, such as density and evaporation rates, but they do not accurately explain the mechanism by which CFCs reach the stratosphere. Focusing on the stability and longevity of CFCs is crucial as it directly correlates to their ability to make it to the stratosphere and cause environmental harm.