What are the components that make up the sides and ends of a casket shell?

The correct choice, body panels, refers specifically to the structural components that form the sides and ends of a casket shell. These panels are crucial as they provide the main structure and aesthetic appearance of the casket. Typically, the body panels are made from materials like wood or metal and are shaped and joined to create a cohesive design.

In the context of casket construction, body panels serve not only to contain and protect the deceased but also play a key role in the overall visual presentation of the casket. The design of these panels can vary widely, impacting both the style and cost of the casket.

The other options, while related to casket construction, represent different aspects. Cap panels are the parts of the casket top, bridging supports provide additional strength between sections, and finishing treatments refer to the final aesthetic enhancements applied to the surface. These components each play their own role, but they do not directly constitute the sides and ends of the casket shell itself, highlighting why body panels is the most accurate answer.