Ghaghara River is a major tributary of which great river?

Correct answer: Ganga

Option C is correct because the Ghaghara is a major Himalayan tributary of the Ganga. It rises in the high Himalayan region, flows through Nepal and northern India, and joins the Ganga in the Gangetic plain. In the usual river-system classification, Ghaghara, Gandak and Kosi are important northern or left-bank tributaries of the Ganga. Narmada and Krishna are major peninsular rivers with separate drainage basins, while the Brahmaputra belongs to a different Himalayan river system and joins the Ganga system farther downstream through the Padma in Bangladesh. Therefore, the direct parent river asked here is the Ganga.