The correct answer is: a) Ahom rule.
The Paik system was a system of military conscription and land tenure in the Ahom kingdom of Assam. It was introduced by the Ahom king Suhungmung in the 16th century. Under the Paik system, all able-bodied men were required to serve in the army for a period of three years. In return, they were given land and a share of the produce. The Paik system was a very effective system of defense and administration, and it helped the Ahom kingdom to expand and consolidate its power.
The Pala Dynasty was a dynasty that ruled over Bengal from the 8th to the 12th centuries. The Varman Dynasty was a dynasty that ruled over Kamarupa (present-day Assam) from the 4th to the 12th centuries. The Chutiya Kingdom was a kingdom that ruled over parts of Assam from the 13th to the 16th centuries. None of these dynasties had a system of military conscription and land tenure similar to the Paik system.