What components are included in the definition of fenestration?

Fenestration refers to the arrangement and proportion of openings in a building, primarily involving windows and doors. The correct choice encompasses all the listed components, which collectively make up the various types of openings that can be considered part of fenestration.

Skylights and roof windows, for instance, are specifically designed to allow natural light into the building from above. They are essential in architectural design for enhancing illumination and, in some cases, ventilation. Opaque doors, vertical windows, and glass blocks also play a crucial role in fenestration, as they contribute to the aesthetics and functionality of a structure, while also facilitating light entry and views.

By including all of these components in the definition of fenestration, the answer captures the full breadth of elements that contribute to a building's opening systems, which is integral to understanding how light and access interact within residential constructions. Thus, recognizing that all of the mentioned components fall under the fenestration umbrella underscores their importance in both design and building science.