Option d is the correct answer. Shams ud-Din Iltutmish earned the moniker 'a slave of a slave.' Sold into slavery as a young boy, Iltutmish spent his early life in Bukhara and Ghazni under multiple masters. In the late 1190s, Qutb ud-Din Aibak, a Ghurid slavecommander, purchased him in Delhi, furthering his status as a slave of a slave. Thriving under Aibak's tutelage, he received the significant iqta' of Badaun. His actions against the Khokhar rebels in 1205-1206 captured the attention of the Ghurid ruler Muhammad of Ghor, who freed him even before Aibak's manumission.