The correct answer is: a) Ahom expansion.
The Ahoms were a Tai people who migrated from present-day Yunnan in China to Assam in the 13th century. They established the Ahom kingdom, which ruled over much of Assam for over 600 years. The Jaintia kingdom was a neighboring kingdom that was located in the present-day state of Meghalaya. The Jaintia rulers were known for their resistance to Ahom expansion. They fought several wars against the Ahoms and were able to maintain their independence for centuries.
The other options are incorrect. The Burmese invaded Assam in the 18th century, but the Jaintia kingdom was not affected by these invasions. The British colonial rule began in Assam in the 19th century, but the Jaintia kingdom was not directly ruled by the British. The Mughal influence was limited to the northern part of Assam, and the Jaintia kingdom was not affected by this influence.
The Jaintia kingdom was a powerful kingdom that was able to maintain its independence for centuries. The Jaintia rulers were known for their resistance to Ahom expansion. They fought several wars against the Ahoms and were able to maintain their independence for centuries. The Jaintia kingdom was a significant kingdom in the history of Assam.