Answer:Choked
Explanation: I think choked us the answer because it represents a strong word for something powerful.
I believe the answer is D.
The correct answer is letter C. It is an effect caused by some factors that are not clearly stated in this sentence. Greenhouse gases would probably be the effect in the sentence that the writer is probably talking about. The necessary causes are also probably highlighted but they are not given in the question. Assuming that you are looking for this thought.
Answer:
He spends the weekends playing guitar .