The most plausible explanation for the location of the Thar Desert in Western India is option 3 - the absence of mountains to the North of Rajasthan to cause orographic rainfall in it.

Orographic rainfall occurs when moist air is forced upwards by mountains, causing it to cool and condense into rain. In the case of the Thar Desert, there are no significant mountains to the north of Rajasthan. This means that the region does not receive much orographic rainfall, which is essential for supporting vegetation and preventing the formation of a desert.

Options 1 and 2 do not directly explain the location of the Thar Desert. While sand dunes and evaporation of moisture by heat may contribute to the aridity of the desert, they do not explain why it is specifically located in Western India.

Option 4 also does not provide a direct explanation for the location of the Thar Desert. While the South-West Monsoon may bring moisture to the region, it is the absence of orographic rainfall due to the lack of mountains that is the primary reason for the formation of the desert.

In conclusion, the absence of mountains to the north of Rajasthan that would cause orographic rainfall is the most plausible explanation for the location of the Thar Desert in Western India.