What constitutes the rear end frame of a container?

The rear end frame of a container is fundamentally defined by the structural components that make up its rear section. The correct answer highlights the door sill, which is the bottom horizontal member that provides structural integrity when the doors are closed. It is joined to the door header at the top, which is the upper horizontal part of the door frame, and the rear corner posts that provide vertical support.

This combination of components is essential for ensuring that the doors function properly and securely while also maintaining the overall strength and stability of the container. The integrity of the rear frame is crucial during loading, unloading, and transport, as it helps withstand various stresses and impacts.

This specification differs from the other options where components mentioned, like bottom or top side rails, may contribute to the overall structure of the container but do not specifically define the rear end frame. Each of those elements serves different functions and does not encompass the complete assembly that constitutes the rear end frame.