Regional division by R.L. Singh depends on

Correct option is D

The regional division proposed by R.L. Singh, a prominent Indian geographer, depends on more than one of the above factors, including geological structure, physiographic structure, and location. Singh's approach to regional division is comprehensive, considering various aspects that influence the spatial characteristics and differentiation of regions. Geological structure affects the region's landforms and soil types; physiographic structure involves the study of physical landscapes and their processes, which helps in understanding the topography; and location contributes to the climatic, cultural, and economic attributes of the region. By integrating these elements, R.L. Singh's methodology for regional division provides a holistic view of geographic areas, emphasizing the interconnectedness of physical and human environments.