In the passage, the social context serves primarily to characterize the typical behaviors of the wealthy elite. The narrator reflects on the house-party at Easeby, noting that the attendees were all law-abiding and suggesting that the environment is one of propriety and genteel living. This social setting emphasizes the contrast between the upper-class lifestyle and potentially scandalous activities that might be expected in a more raucous context. Therefore, the best answer is:
to characterize the typical behaviors of the wealthy elite.