Question

parlor alone.
running her feather duster over ornate picture frames, frances heard a rustling behind her. she whirled around, looking for a mouse. mrs. bailey loathed mice, developing elaborate systems for their entrapment. frances saw nothing, but continued to hear a faint scratching sound. she crept into the shadows, gasping when her sleeve brushed the edge of the sheeted piano.
she took a deep breath and tried to steady her beating heart. its just a mouse, she reminded herself.
but as she scanned for a furry creature where the dark mahogany wall met the floor, she found something else. carved into the wall was a rectangle a few feet high. the edges lined up with the pattern of the wall, making it nearly invisible. a hidden door, thought frances, reaching out and touching a rusted latch. the rustling, now louder than any mouse, was clearly coming from the other side.
how does being in the parlor affect frances?
being in the parlor makes frances wish she had not shared ghost stories.
being in the parlor makes frances resentful of mrs. bailey for making her clean it.
being in the parlor strengthens francess belief that the mansion is haunted.

Explanation:

Frances hears rustling, thinks it's a mouse (Mrs. Bailey's mouse - trapping context), then finds a hidden door with louder rustling. The suspenseful elements (rustling, hidden door) suggest a spooky, possibly haunted atmosphere. There's no mention of ghost - story sharing or resentment towards Mrs. Bailey for cleaning. The focus is on the spooky, hidden - door discovery which implies a haunted - like situation.

Answer:

Being in the parlor strengthens Frances's belief that the mansion is haunted.