The correct answer is: c) 13th century.
Sukaphaa founded the Ahom Kingdom in Assam in 1228. He was a Shan prince from Mong Mao in present-day Yunnan, China. He led a group of Shan people to Assam in search of a new home. They arrived in Assam in 1228 and defeated the local rulers. Sukaphaa then established the Ahom Kingdom in Sibsagar. The Ahom Kingdom was a powerful kingdom that ruled Assam for over 600 years.
The other options are incorrect. The 10th century was the time of the Pala Empire in Bengal. The 12th century was the time of the Sena Empire in Bengal. The 15th century was the time of the Koch Kingdom in Assam.