Majuli, the world’s largest river island, is known for its:

Vaishnavite Sattras (monasteries)
Tea plantations
Wildlife sanctuary
Ancient temples

The correct answer is: a) Vaishnavite Sattras (monasteries).

Majuli is an island in the Brahmaputra River in Assam, India. It is the world’s largest river island, and is home to a unique culture and history. The island is known for its Vaishnavite Sattras, which are monasteries that are home to a community of monks and nuns. The Sattras are important centers of learning and culture, and play a vital role in the lives of the people of Majuli.

The other options are incorrect because:

  • Tea plantations are not a major feature of Majuli.
  • There is no wildlife sanctuary on Majuli.
  • There are some ancient temples on Majuli, but they are not as well-known as the Sattras.