What was the shape of the mark on Mrs. Starch's chin?

The correct choice, which describes the mark on Mrs. Starch's chin as resembling an anvil, aligns with the context of how the mark serves as a distinctive feature of her character. A mark shaped like an anvil suggests a strong and solid persona, which is often associated with authority and resilience. This shape contributes to the portrayal of her character in the narrative, symbolizing her robust nature and potentially her role in the story, possibly hinting at her unwavering presence in the school environment.

While other shapes like circle, star, or diamond carry their own symbolic meanings, they do not effectively encapsulate the specific characteristics or personality traits attributed to Mrs. Starch in this context. The anvil shape is thus not only a physical description but also contributes to the reader's understanding of her role and character qualities in the story.