Final answer:
The narrator frequently uses the word C. 'creeping' to describe the movement of the woman in the wallpaper.
Step-by-step explanation:
The word frequently used by the narrator to describe the movement of the woman in the wallpaper is creeping. This term appears several times throughout the text, indicating a stealthy, slow, and perhaps unsettling movement that is central to the narrator's obsession with the figure in the wallpaper. Phrases like "I see her on that long shaded lane, creeping up and down" and "It must be very humiliating to be caught creeping by daylight" highlight the repetitive use of the word.