Based on the stage directions at the beginning of the passage, what inference can be made about the social standing of these characters?

Stage Set: The octagon room at Sir Robert Chiltern's house in Grosvenor Square, a large garden square in London.

[The room is brilliantly lighted and full of guests, and at the top of the staircase stands Lady Chiltern, a woman of about twenty-seven years of age, who receives the guests as they come up. Over the well of the staircase hangs a great chandelier with wax lights, which illuminate a large eighteenth-century French tapestry—representing the Triumph of Love, from a design by Boucher—that is stretched on the staircase wall. On the right is the entrance to the music room. The sound of a string quartet is faintly heard. The entrance on the left leads to other reception rooms. Mrs. Marchmont and Lady Basildon are seated together on a King Louis the Sixteenth sofa.] MRS. MARCHMONT: Going on to the Hartlocks' tonight, Margaret? LADY BASILDON: I suppose so. Are you? MRS. MARCHMONT: Yes. Horribly banal parties they give, don't they? LADY BASILDON: Horribly banal! Never know why I go. Never know why I go anywhere. They're all so tedious. MRS. MARCHMONT: I come here to be educated. LADY BASILDON: Ah! I hate being educated! MRS. MARCHMONT: So do I. It puts one almost on a level with the commercial classes, doesn't it? But dear Gertrude Chiltern is always telling me that I should have some serious purpose in life. So I come here to try to find one. LADY BASILDON: [Looking round through her spectacles.] I don't see anybody here tonight whom one could possibly call a serious purpose. The man whom I sat next to at dinner talked to me about his wife the whole time. MRS. MARCHMONT: How very trivial of him! LADY BASILDON: Terribly trivial! What did the man next to you talk about? MRS. MARCHMONT: About myself. LADY BASILDON: [Languidly.] And were you interested? MRS. MARCHMONT: [Shaking her head.] Not in the smallest degree. LADY BASILDON: What martyrs we are, dear Margaret! MRS. MARCHMONT: [Rising.] And how well it becomes us, Olivia!