Which architectural term refers to grand buildings built for public or ceremonial use in ancient Rome?

The correct choice highlights the term "templa," which refers specifically to grand buildings in ancient Rome dedicated to religious worship and public ceremonies. Temples served as important civic centers where significant rituals and gatherings occurred, aligning with the cultural priorities of Roman society. The grandeur of these structures often reflected the power and influence of the deities honored within, as well as the community's wealth and devotion.

In contrast, other terms relate to different architectural types. “Insulae” are multi-story apartment buildings designed for residential purposes, commonly housing the lower to middle-class citizens. “Regio” refers to a district or region and does not denote a specific building type. “Domus” signifies private homes for the wealthier class, emphasizing domestic life rather than public use. Understanding these distinctions underscores why "templa" is the most fitting choice for grand public and ceremonial buildings in ancient Rome.