Correct Option (C)
Statement I is correct. Subtropical and temperate regions generally exhibit higher concentrations of atmospheric dust particles compared to equatorial and polar regions. This is primarily due to the prevalence of dry climates, often leading to sparse vegetation cover. The presence of strong, dry winds in these zones facilitates the erosion of dry soil and the suspension of dust into the atmosphere. Convectional air currents further aid in lifting these particles to considerable heights. In contrast, equatorial regions are characterized by high humidity and dense vegetation, which suppress dust generation, while polar regions are largely covered by ice and snow, limiting the availability of loose dust.
Statement II is not correct. Subtropical and temperate areas are frequently characterized by the presence of dry winds, not less. These regions often lie under persistent high-pressure belts, leading to arid or semi-arid conditions. The dry winds originating from these high-pressure systems are significant contributors to the mobilization and transport of dust, making the assertion of "less dry winds" factually inaccurate.
Incorrect Options
Options (1) and (2) are incorrect because Statement II is factually incorrect.
Option (4) is incorrect because Statement I is factually correct.