With reference to India, Didwana, Kuchaman, Sargol and Khatu are the names of

Answer: (d) Saline Lakes

They are saline lakes of the Thar region.

The idea

In a dry closed basin, water can enter a lake without having a permanent outlet to the sea. Evaporation removes water but leaves dissolved salts behind. Repeated concentration produces a saline lake, even far inland.

Runoff enters a depression → Water dissolves salts → Little water escapes through an outlet → Strong evaporation removes water → Salts become concentrated → Salt crust remains when the lake dries

Why the others are wrong

(a) Rajasthan has no glaciers.

(b) Rajasthan has no mangroves.

(c) Only Sambhar is a Ramsar site among Rajasthan’s salt lakes.

The trap

Sambhar (a salt lake) is a Ramsar site, which makes (c) tempting.

Also know

Sambhar, Pachpadra and Lunkaransar belong to the Rajasthan salt-lake family. A saline lake is a physical type; a Ramsar site is an international designation, so the two labels can overlap. Chilika is also saline or brackish, but its coastal sea connection gives it a different setting.