The use of two or more maps that are digitally or manually superimposed and registered...

Overlay analysis involves superimposing multiple maps, aligned to a common coordinate system, to analyze relationships between geographic features (e.g., land use and flood zones). Option C (an overlay) correctly describes this technique, widely used in GIS and planning. The APA’sAICP Certification Exam Content Outline(2022), under “Research and Assessment Methods,” defines an overlay as “the process of superimposing two or more maps to analyze spatial relationships between features.” Option A (theme) refers to a map layer, not the process. Option B (buffer) is a proximity analysis tool, not superimposition. Option D (merge) combines datasets but doesn’t involve spatial superimposition. TheCPC Study Manual(2024) states, “Overlay analysis superimposes maps to show relationships between features in the same geographic space,” supporting option C.