Which component is used to divide a door into multiple panels?

The correct component used to divide a door into multiple panels is the mullion. Mullions are vertical or horizontal elements that separate and support panels or lights in a door or window. In the context of doors, when multiple panels are desired for aesthetic or functional reasons, mullions are installed to create those distinct sections or divisions.

This usage enhances the door's design, allowing for more intricate styles and helping to create a more appealing visual impact. Additionally, mullions also play a structural role in maintaining the integrity of the door.

The other components mentioned have different functions: stiles are the vertical parts that run along the sides of the door; rails are the horizontal components across the top and bottom; and framing refers generally to the overall structure that holds everything together. Understanding these components and their specific roles is essential for grasping how doors are constructed and styled.