Name the King (Sultan) who built the Qutub Minar in Delhi.
a. Muhammad Ghori
b. Sultan Iltutmish
c. Sultan Qutub-ud-din Aibak
d. None of these

Hint: The Sultan was initially King Mu'izz ad-Din Muhammad Ghori’s General. He was in possession of the Ghurid territories in northern India and became the ruler of an independent kingdom after the death of Mu'izz ad-Din, which developed into the Mamluk dynasty-ruled Delhi Sultanate.

Complete solution:
Founded to celebrate as a ‘Victory Tower’ for Muhammad Ghori's victory over the Rajput king, Prithviraj Chauhan, in 1192 AD, by his then viceroy, Qutub-ud-din Aibak. Its construction also marked the beginning in India of Muslim rule.

Aibak was succeeded by Aram Shah, and then by Iltutmish, his former slave, who converted India's loosely-held Ghurid territories into the powerful Sultanate of Delhi. The Qutub Minar in Delhi and the Adhai Din Ka Jhonpra in Ajmer are known for having commissioned Aibak.

- It was built on the ruins of Lal Kot, the Dhillika citadel.
- In 1199, Qutub-ud-din Aibak, a deputy of Muhammad of Ghor, who established the Delhi Sultanate after the death of Muhammad of Ghor, began the construction of the first floor of the Qutub Minar. There are inscriptions on this floor, praising Muhammad of Ghor.
- A further three floors were completed by Aibak 's successor and son-in-law, Shamsuddin Iltutmish.
- The ruler at the time, Firuz Shah Tughlaq, replaced the damaged storey after a lightning strike in 1369 damaged the then top storey and added one more.
- An entrance was also added by Sher Shah Suri when he ruled and the Mughal emperor Humayun was in exile.

Hence, the correct answer is option c.

Note:
 It is commonly believed that the tower is named after Qutub-ud-din Aibak, who started it, but it is also possible that a 13th-century Sufi saint is named after Khwaja Qutbuddin Bakhtiar Kaki as Shamsuddin Iltutmish was his devotee.