Bhakra Nangal, Hirakud and Kosi projects are situated on the rivers.

Answer: (a) Sutlej, Mahanadi and Kosi

Bhakra Nangal – Sutlej; Hirakud – Mahanadi; Kosi barrage – Kosi.

The idea

A dam, reservoir and river may have three different names. Start with the river carrying the project, then attach the reservoir name if needed. Nearby rivers in the same drainage system cannot be swapped just because their water is linked by canals.

Why the others are wrong

(b) The Kosi project is not on the Purna.

(c) Bhakra is on the Sutlej, not the Mahanadi.

(d) The order is scrambled — Bhakra is not on the Beas.

The trap

Beas and Sutlej are neighbours — Pong dam is on the Beas, Bhakra on the Sutlej.

Elimination technique

Bhakra’s Sutlej location removes (c) and (d). Hirakud’s Mahanadi location leaves (a) and (b); Kosi’s own river then settles that pair.

Also know

Gobind Sagar is the Bhakra reservoir, while Pong creates Maharana Pratap Sagar on the Beas. Hirakud is upstream of the Mahanadi delta near Sambalpur. Kosi barrage is in Nepal near the Indian border town of Bhimnagar; barrage and storage-dam functions should be distinguished.