Dhauliganga meets Alaknanda at which Prayag?

Correct answer: Vishnuprayag

The direct answer is D, Vishnuprayag. In the Alaknanda river system, Dhauliganga joins the Alaknanda at Vishnuprayag. The reasoning is a river-confluence match: identify the tributary, Dhauliganga; identify the main river, Alaknanda; then recall the Prayag where they meet—Vishnuprayag. Option A, Rudraprayag, is wrong because Mandakini joins the Alaknanda there. Option B, Karnaprayag, is wrong because Pindar joins the Alaknanda there. Option C, Devprayag, is wrong for this pairing because Bhagirathi joins Alaknanda at Devprayag, and their meeting forms the Ganga. Option D, Vishnuprayag, is correct because it is the confluence of Dhauliganga and Alaknanda. These Prayags are important Uttarakhand geography facts, so memorising the tributary–Prayag pairs prevents confusion. Memory chain: Vishnuprayag–Dhauliganga, Nandprayag–Nandakini, Karnaprayag–Pindar, Rudraprayag–Mandakini, Devprayag–Bhagirathi.