It can be inferred from the passage that the hypothesis linking carbon dioxide to non-sunspot-related climate change is based on which of the following assumptions?
A.
The effect of sunspots on the climate has actually diminished with the development of greenhouse gases.
B.
There are no phenomena other than carbon-dioxide and solar cycles that could affect climate change in a significant manner.
C.
The increase of solar minima over the past two decades has probably exacerbated the warming effects of greenhouse gases.
D.
Carbon-dioxide did not exist in significant quantities in the environment prior to industrialization.
E.
Carbon-dioxide levels in the Earth's atmosphere rise and fall according to the same eleven-year cycles as sunspots.