The correct answer is: A. Delhi
Delhi was the most important iqta during Iltutmish’s reign from both a military and economic point of view. It was the capital of the Delhi Sultanate and the seat of Iltutmish’s power. Delhi was also a major commercial center and a hub for trade routes between India and Central Asia.
Hansi was an important iqta from a military point of view, as it was located on the border between the Delhi Sultanate and the Ghurid Empire. However, it was not as important economically as Delhi.
Narnaul and Rewari were both important iqtas from an economic point of view, as they were located in fertile regions and produced a surplus of agricultural goods. However, they were not as important militarily as Delhi.
In conclusion, Delhi was the most important iqta during Iltutmish’s reign from both a military and economic point of view.