The correct answer is only a is correct. Explanation & Key Takeaways: Reasons responsible for distribution in western part of Rajasthan minerals like limestone, gypsum and mineral salts reserves: • Western part of Rajasthan was submerged under sea water during the Permocarboniferous period, which led to the deposition of various minerals. The sea water carried sedimentary materials that settled and formed layers over millions of years, resulting in the accumulation of minerals like limestone, gypsum, and mineral salts. • The region receives low rainfall, which is a crucial factor for the formation and preservation of minerals. The scarcity of water limits the leaching and erosion processes, allowing the minerals to remain relatively undisturbed and concentrated in the area. • The hot and dry climate of the western part of Rajasthan also plays a role in the preservation of minerals. High temperatures and low humidity contribute to the evaporation of water bodies, leading to the deposition of mineral salts. Additionally, the arid conditions prevent excessive weathering and erosion, allowing the minerals to remain intact. • The geological structure of the region, including the presence of sedimentary basins and fault lines, has influenced the occurrence and distribution of minerals. These geological features provide favorable conditions for the deposition and accumulation of limestone, gypsum, and mineral salts.