Z-Order Curves (Geohashing) map 2D data to 1D strings for indexing. What is their primary weakness?

1. A They are fundamentally unable to handle floating-point numeric coordinates, requiring them to be converted to less precise integer representations.
2. B They are typically significantly larger in terms of physical disk footprint than comparable R-Tree structures due to their reliance on raw string literals.
3. C Discontinuity issues mean that points which are physically close in 2D space can end up very far apart in the 1D sort order, leading to inefficient query ranges.
4. D They strictly support point-based geodata and are mathematically incapable of representing or indexing complex spatial polygons or multi-dimensional lines.