Final answer:
Option (1), Lucy Steele telling the servant Thomas about her secret marriage shows her underhandedness or wiliness, as this reveals a clandestine action that involves deceit or cunning in the societal context of the story.
Step-by-step explanation:
When Lucy Steele spoke to the servant Thomas, telling him she was married to Mr. Ferrars, it could demonstrate her underhandedness or wiliness. This is because Lucy is revealing a secret marriage which would have been considered quite scandalous in the context of Jane Austen's society, thereby acting in a way that is deceitful or cunning.
The act does not particularly exhibit a sense of humor or thoughtfulness, as these traits do not align with the secrecy and potential manipulation involved in her actions.