Final answer:
Anne may view her mother's disapproval of Margot sharing a room with Mr. Dussel as a sign of being overly protective.
Step-by-step explanation:
Concerning Mrs. Frank's disapproval of Margot sharing a room with Mr. Dussel, Anne might interpret her mother's response as her being overly protective. This is a possibility because as Anne tries to understand adulthood and boundaries, she might see her mother's protective instincts as unnecessary or excessive, leading her to conclude that option a. is the most likely interpretation.