Which type of casket shell would be narrower at the base compared to the opening?

The correct choice is the flaring square shell, which is characterized by its shape that narrows at the base compared to the wider opening at the top. This design creates a visually striking silhouette and is often used to convey a sense of elegance and distinction. The flaring shape allows for a more spacious interior at the top while providing a tapering appearance towards the bottom.

This design contrast is particularly important in the context of caskets, as it can influence both aesthetic preferences and the overall presentation. The other shell types do not exhibit this specific narrowing feature; a circular shell maintains a consistent width, a flat rectangular shell has straight sides throughout, and a traditional design shell often follows standard dimensions without the distinctive flare seen in the square shell.