0. The longest dam in India is
Hirakud Dam, built across the Mahanadi River in Odisha, is the longest dam in India, stretching over 25 kilometers.
A. Bhakra Dam – Incorrect. One of the tallest, but not the longest.
B. Nagarjuna Sagar Dam – Incorrect. Large, but shorter in length than Hirakud.
C. Hirakud Dam – Correct. It is the longest dam in the country.
D. Kosi Dam – Incorrect. Important in Bihar, but not the longest.