D, summary of information. A discovery is not accurate, because this is a research paper, meaning you are researching something that has already happened. B isn't correct, because recommendations are generally only used for persuasive writing. C isn't correct, because a deeper question in the ending wouldn't make sense, as you want to cover everything in the body. D is your correct choice, since you always want to summarize information at the end of a research paper.
The setting which begins to answer your question is the sentence that begins "Most conversations between husband and wife ... " this is near the beginning.
The real core of your question comes with "This aloofness ... " which shows how he handles the disputes with his wife. This is followed by "He attained this by ... " which tells exactly how the aloofness came about. Finally he surrounds himself with people that insulate him from the fights he has will his wife. His bridge games probably insure that he does not have to talk to her.
In a sentence, there is always a Subject and a Predicate. A subject is the main topic of a sentence, while the predicate is what the subject is pertained to. In the sentence: Relaxing is not as easy as it looks. The subject is Relaxing which is also considered a gerund. And the predicate is 'is not as easy as it looks'.
I'm not the best at this but I'm guessing Semi-formal
