The correct answer is option 3: Sir Thomas Munro. The Ryotwari system was introduced in Madras by Sir Thomas Munro. The Ryotwari system was a land revenue system implemented during British colonial rule in India. Under this system, individual farmers or "ryots" were recognized as the direct owners of the land they cultivated and were responsible for paying a fixed revenue to the British government. This system was a departure from the earlier zamindari system, where intermediary landowners collected revenue from the farmers. Sir Thomas Munro, as a British administrator, implemented the Ryotwari system in Madras presidency in 1820. It aimed to simplify the revenue collection process and create a direct relationship between the government and the farmers.