The Thar Desert, the largest desert of India, lies mainly in the state of

The Thar or Great Indian Desert covers western Rajasthan in a major part, extending into Gujarat, Haryana and Punjab as well as Pakistan. Since the largest part lies in Rajasthan, that is the correct answer. The other states hold only its fringes, where rainfall is slightly higher and irrigation canals, such as the Indira Gandhi Canal, have changed land use.