What type of drawing is primarily used for high-level project overviews?

The correct choice for a drawing primarily used for high-level project overviews is a block diagram. Block diagrams provide a simplified representation of a system, using labeled rectangles, squares, or other shapes to represent components and lines to indicate connections and relationships between those components. This type of diagram is particularly useful for conveying the overall structure and functionality of a system without getting bogged down in the minute details.

Block diagrams serve as a tool for both visual communication and initial planning, allowing stakeholders to grasp the broader concepts of the project at a glance. They focus on the main components and their interrelations rather than the intricate specifics of wiring or connections, making them effective for overviews and presentations.

In contrast, wiring line diagrams are more technical and detailed, focusing on the specific layout and connections of electrical wiring, which is not suitable for an overview. Detailed scheme drawings provide intricate designs and layout plans, while mixed-scheme drawings may integrate both detailed and simplified elements but are not as universally recognized for high-level overviews as block diagrams.