Concept:Paradeep Port is a major port on the eastern coast, situated at the delta of the Mahanadi River in Odisha.Explanation:The port lies at the mouth of the Mahanadi River, where it forms a delta before entering the Bay of Bengal.The Mahanadi River delta is the correct location for Paradeep Port.Other options are incorrect: Baitarani is a separate Odisha river (tributary of Brahmani); Rihand is a tributary of Son in Chhattisgarh; Ganga is far to the north.Answer:C. Mahanadi