It would be primary since the writer himself is getting the information from a direct source.
The correct answer is option b, that is, the addition of carbon dioxide to the atmosphere.
If the concentration of carbon dioxide upsurges in the atmosphere due to the enhanced rate of outgassing, there will be a constant elevation in the global temperature. The elevating temperature and more dissolved carbon dioxide will result in enhanced weathering of crystal rocks as a consequence of faster rate of reactions and greater acidity.
Hopefully this will help and it's what you are looking for.
Answer:
PROMOTER is a DNA sequence where RNA polymerase binds and begins the process of transcription. ENHANCER is a D N A sequence that binds regulatory proteins that interact with promoter-bound proteins to activate transcription.
Explanation: