Explanation:

- The Damodar River is a significant river in eastern India, known for its tributary role to another major river.

- Ganga: One of the holiest rivers in India, flowing across the northern plains. Many major rivers join the Ganga, but Damodar is not directly one of them.

- Hugli: A distributary of the Ganga, flowing through West Bengal. The Damodar River indeed joins the Hugli River in its lower course.

- Padma: This is the name of the Ganga River in Bangladesh before it merges with the Brahmaputra, not directly linked to Damodar.

- Suvarn Rekha: This is a separate river, not connected as a tributary to the Damodar.

Thus, the correct answer is option 2: Hugli. .