The correct answer is option 4 - Brahmaputra.

Majuli is a river island located in the Brahmaputra River, which is one of the major rivers in the Indian subcontinent. The Brahmaputra River flows through Tibet, India, and Bangladesh, and is known for its strong currents and high water volume. Majuli is situated in the Indian state of Assam and is considered to be the largest river island in the world.

Option 1 - Jamuna, is not the correct answer. Jamuna is the name used for the Brahmaputra River in Bangladesh.

Option 2 - Padma, is also not the correct answer. Padma is the name given to the Ganges River in Bangladesh.

Option 3 - Ganga, is not the correct answer. Ganga, also known as the Ganges, is another major river in the Indian subcontinent but Majuli is not located in this river.

Overall, Majuli is located in the Brahmaputra River, making option 4 the correct answer.