The correct answer is option 4 - the winds do not come across any barriers to cause the necessary uplift to cool the wind. Rajasthan receives very little rain because the winds that carry moisture from the Arabian Sea do not encounter any geographical barriers in the region. Geographical barriers such as mountains act as obstacles for the winds and cause them to rise, cool down, and release their moisture as rain. However, Rajasthan is mostly flat and lacks such barriers, which prevents the necessary uplift of the winds and the subsequent cooling to occur. As a result, the winds remain dry, and Rajasthan experiences scarce rainfall. Options 1, 2, and 3 are not accurate explanations for Rajasthan`s low rainfall.