The correct response is: People tend to act as if Rosemary is always right because of her wealth.
This interpretation is supported by the way the shop attendant promptly removes the lilac from sight upon Rosemary's request, suggesting that her opinions and preferences hold significant weight, likely due to her affluence. The interaction illustrates a dynamic where Rosemary's wealth allows her to assert her desires without question, highlighting how her status influences the treatment she receives from others.