Explanation:

Didwana, Kuchaman, Sargol, and Khatu are saline lakes located in the state of Rajasthan, India.

Saline lakes have a high concentration of salts and are important for various ecological and economic reasons.

Rajasthan, due to its arid climate and unique geological formations, has several saline lakes and playas that are important for salt production and as habitats for certain specialized species.

Therefore, the correct answer is saline lakes.