The Delhi sultanate of the twelfth century could not effectively quell their Indian subjects because: a. disintegration of the Abbasid Dynasty to a rival Sunni faction left no centralized chain of command. b. the Rajput engrained considerable resistance to the Muslims by appealing to both Buddhists and Hindus. c. Islamic forces were split between India and trying to fight the Crusades in the Mediterranean. d. the arrival of the Mongol forces on the northwest frontier.