The largest river island in the world, Majuli, is located in which river of Assam?

The correct answer is: c) Brahmaputra.

Majuli is the largest river island in the world, located in the Brahmaputra River in Assam, India. It is home to a unique culture and ecosystem, and is a popular tourist destination.

The other options are incorrect because:

• Dhansiri is a river in Assam, but it is not as large as Majuli.
• Manas is a national park in Assam, but it is not a river.
• Barak is a river in Assam, but it is not as large as Majuli.