The correct option is A Assam
The longest river bridge in India is the Dhola-Sadia Bridge in Assam. It is also called Bhupen Hazarika Bridge. It is a three-lane bridge stretching 9.15 kilometre built over river Lohit, which is a tributary of the Brahmaputra river. The bridge connects Sadia, which is 540 Km from Guwahati and Dhola, situated 300 Km from Itanagar.