Read the excerpt from Act III of The Importance of Being Earnest . Jack: [In a clear, cold voice.] Miss Cardew is the grand-daughter of the late Mr. Thomas Cardew of 149 Belgrave Square, S.W.; Gervase Park, Dorking, Surrey; and the Sporran, Fifeshire, N.B. Lady Bracknell: That sounds not unsatisfactory. Three addresses always inspire confidence, even in tradesmen. But what proof have I of their authenticity? Jack: I have carefully preserved the Court Guides of the period. They are open to your inspection, Lady Bracknell. Lady Bracknell: [Grimly.] I have known strange errors in that publication. Jack: Miss Cardew’s family solicitors are Messrs. Markby, Markby, and Markby. Lady Bracknell: Markby, Markby, and Markby? A firm of the very highest position in their profession. Indeed I am told that one of the Mr. Markby’s is occasionally to be seen at dinner parties. So far I am satisfied. What does this excerpt most clearly convey about Lady Bracknell?