The correct answer is Tomb of Sultan Balban.
Key Points
- Tomb of Sultan Balban:
- It is located in Mehrauli, New Delhi.
- It is considered to be the first structure to have a true dome and an arch.

Additional Information
- Adhai din ka Jhonpra:
- It is one of the oldest mosques in India and is located in the city of Ajmer, Rajasthan.
- It is built by Qutb-ud-din Aibak.
- Quwwat ul Islam Mosque:
- It is located within the Qutub Minar complex at Mehrauli in Delhi.
- It was built by the Qutub-ud-din Aibak.
- Alai Darwaza:
- It is the southern gateway of the Quwwat-ul-Islam Mosque.
- It is made up of red sandstone.
- It was built by Alauddin Khalji in 1311 AD.
- It is located in the Qutb complex, Mehrauli, Delhi.
- Alai Minar An incomplete Minar ambitiously started by Sultan but was left incomplete.


