Various landforms observed on the surface of the earth are due to the: 1. differences in the type and structure of the crustal material 2. differences in the land forming processes 3. differential rates of the processes at different places on the Earth’s surface Select the correct answer using the code given below:

The diversity of landforms on the Earth's surface is the result of a complex interplay between internal and external forces. According to geomorphic principles, differences in the type and structure of crustal materials (lithology and structural variations) significantly influence how landscapes evolve [3]. Furthermore, landforms are shaped by various geomorphic processes, including endogenic forces like diastrophism and volcanism, and exogenic processes such as weathering, erosion, and deposition [2]. Crucially, these processes do not operate uniformly; their rates of operation vary across different regions due to thermal gradients, climatic variations, and gravitational stresses [4]. This differential rate of geomorphic action at different places ensures that the Earth's surface configuration remains dynamic and varied [2]. Therefore, all three factors—material structure, the nature of the processes, and their varying rates—are fundamental to landform development.

Sources

1. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 6: Geomorphic Movements > 6. Geomorphic Movements > p. 78
2. [3] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 5: Geomorphic Processes > GEOMORPHIC PROCESSES > p. 38
3. [4] https://www.sciencedirect.com/science/article/abs/pii/S0169555X25000170