Correct Answer: (b) Iltutmish
Note: Iltutmish was the first Sultan of Delhi who received the investiture from Caliph. In 1229 A.D. the Caliph of Baghdad, Al-Muntasir Billah, bestowed on Iltutmish the titles of "Sultan-i-Azam" or the Sultan The Great. Thus, in this way, he was the first legally independent Sultan of Delhi. He was successful in keeping the throne of Delhi safe from the danger of Mongol invasion as well as from the attacks of both Taj al-Dim Yildoiz also spelled Yilduzm Yildoz and Qubacha. He broke up the Rajput powers in the north and established his supremacy over them. He made his rule hereditary, issued coins with his name and made Delhi a beautiful capital. He is said to have introduced first Arabic silver (175 gm) and copper currency which were two basic coins of the sultanate period. Iltutmish belonged to the tribe of Ilbari' in the Eurasian Steppe of Turkestan. Iltutmish was first appointed governor of Badaun in recognition of his sevices during the campaign of Muhammad of Ghur against the Koakhars in 1205-06. Amirali Ismail invited Iltutmish for the coronation in Delhi with the approval of Turkish nobles after the death of Aybak. Iltutmish declared himself Sultan in 1211 A.D.