The correct answer is: a) Sadiya.
The Chutiya Kingdom was a powerful dynasty in eastern Arunachal Pradesh. It was founded in the 13th century by the Chutiya people, who were originally from Assam. The kingdom reached its peak in the 16th century, when it controlled a large part of eastern Arunachal Pradesh and northern Assam. The Chutiya Kingdom was eventually overthrown by the Ahom Kingdom in the 17th century.
Sadiya was the capital of the Chutiya Kingdom. It is located on the banks of the Brahmaputra River in eastern Arunachal Pradesh. Sadiya is a major town in the state and is known for its historical importance.
The other options are incorrect. Itanagar is the capital of Arunachal Pradesh. Tawang is a town in western Arunachal Pradesh. Bomdila is a town in central Arunachal Pradesh.