Q. The most plausible explanation for the location of the Thar desert in western India is....

1. the absence of mountains to the north of Rajasthan to cause orographic rainfall in it
2. the evaporation of moisture by heat
3. that the moisture carried by the South-west monsoon is driven away by the dry upper air current
4. the obstruction caused by the Aravalis to the rain-bearing wind that proceeds to the Ganga Valley