Vertical divisions of windows into different numbers of lights are called?

• A. Mullions
• B. Tracery
• C. Transoms
• D. Archivolts

Answer: (B)

The main concept here is the specific architectural vocabulary for how windows are divided. The vertical divisions that separate a window into multiple panes are called mullions. Mullions are the structural bars that run up and down, creating the number of lights a window has.

Tracery, by contrast, refers to the decorative stonework that forms the pattern of openings in Gothic windows. It often governs the overall arrangement of lights and can include mullions within its tapestry, but it’s describing the decorative network rather than the simple vertical division itself.

Transoms are horizontal bars that divide the window into rows of lights, not vertical divisions. Archivolts are the molded decorative arches framing the interior edge of an arch.

So, for vertical divisions into different numbers of lights, the correct term is mullions.