A comprehensive, in-depth history of architecture has not yet been written because of the widely varying climatic conditions, radically different cultures and ongoing wars, disease and famine.

The correct answer is ancient

Architecture has the purpose of designing and erecting buildings - or other types of built spaces.

Architectural styles are types of classifications used to identify the locations and time periods to which architectural works belong. Several formal characteristics are taken into account, including the influences of other creators' works on each work.

Architectural styles are an artistic form of representing the behavior and customs of a people and an era. Therefore, its aesthetics, proportions, uses and applications of materials and functional and structural techniques characterize each style in particular.

porter is writing economic history because he is focusing on the cost of developing vaccines.