When creating a large-scale map of a river, which vector geometry represents the river accurately?

Using a line to represent the river is the most accurate choice for creating a large-scale map. A line geometry effectively captures the linear nature of a river, illustrating its flow and direction. Lines are particularly advantageous in mapping scenarios where the width of the river is not a primary concern, as they can represent its path succinctly without unnecessary detail.

Polygons and multipart polygons, while useful for areas or regions, are not suitable for depicting features like rivers, which have a defined path and less emphasis on area. Multipoint features could represent discrete points along the river, but they would fail to convey the continuous nature of the river itself. Therefore, a line is the optimal representation to accurately map the river's course.