Which of the following best describes the appearance of a cupola vent?

A cupola vent is best described as a tower-like structure on the roof. This design allows for ventilation and adds aesthetic appeal to a building. Cupolas often sit atop roofs and can come in various sizes and styles, but they generally rise above the main roofline, providing a distinguished architectural feature. Their purpose is not only to enhance airflow and reduce heat buildup in the attic or upper spaces but also to serve as a decorative element.

In contrast, options describing a flat rectangular appearance or a small, wall-mounted unit do not align with the typical design or function of a cupola vent. A round and dome-shaped structure may describe other types of architectural features, like domes or certain vents, but does not capture the distinctive tower-like profile that defines cupola vents.