Option c is the correct answer. Option a is correct: The Iqta system was primarily a revenue collection system used to collect land taxes. This collection was done by Muqtis or Iqtedars. Option b is correct: The Siyasatnama was the source of information for Iqta system. The classical definition of the iqta system has been given by Nizamult Mulk Tusi's Siyasatnama. According to it, the iqta was a revenue assignment that the muqti held at the pleasure of the Sultan. Option c is incorrect: The Muqti and Wali collected revenue from their iqta area. They retained part of revenue for their own expenses, paid the troops maintained by them and sent the surplus (fawazil) to the centre. Hence, the revenue from Iqta was not directly deposited in Sultan's account. Option d is correct: The Provincial administration was headed by the muqti or wali. Muqti was supported to maintain troops out of the revenue collected from Iqta. He leads military campaigns and maintain law and order in their iqtas. Important Tips Iqta System: The Iqta system in India was introduced by the Iltutmish of the Delhi Sultanate. The concept was based on Muhammad Ghori's ideas. Iqta in the Delhi Sultanate means land or land revenue entrusted to a person on specific conditions. Under the Iqta system, the land was divided into several large and small areas called 'iqtas', and the sultan ceded these iqtas to his soldiers, officers, and nobles. The grant of iqta did not imply a right to the land nor was it hereditary though the holders of iqta tended to acquire hereditary rights in Piruz Tughlaq's reign.