I have a different view than captured by your A-E options.
1) The climate, or really the whole earth, has some background rate of change, that itself changes over time.
2) On top of that, there is change, ranging from significant to insignificant depending on the area, caused by humans.
3) This will cause the earth to change at a rate (potentially much) faster than if humans were not here.
None of this, to me, represents a problem in itself. The earth before humans, or at any other point in our history was not some ideal utopia. Humans have inflicted colossal change upon the world since our first day -- we've decimated pests, built cities over forests and dams over rivers, created lakes and removed others, just to name just a few. The world we live in today is anything but "natural".
My primary point of disagreement with those who consider climate change a grave threat is the approach. Rather than setting "reduction targets" and "cutting back", we will, as humans have always done, build solutions to problems as we grow. Whether that's investing in improved desalination technology to provide large quantities of fresh water (due to a demand for water), electric vehicles to reduce localized emissions (due to a demand for clean air), or plant a trillion trees to store carbon (due to a demand for lower temperatures), the key is that for those to be workable options they must represent the growth of humanity, not the decline. There's also vast amount of land in Canada and Russia that at present is undesirable because it is too _cold_.
Humans have survived in horrendously hostile environments and have built upon that the wonderful and wholly unnatural modern lifestyle. Humans have never in history been THIS well resourced to survive despite environmental changes, and I have the utmost confidence we will do exactly that.