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.
My buddie Nathan Hattaway is very well known around this areas of (blank)
What is the question I would be glad to help