Alai Darwaza is a gateway to which of the following historical monument?

Qutub Minar

The correct answer is Option 1- Qutub Minar

The Alai Darwaza is the main gate from the southern side of the Quwwat-ul-Islam Mosque in the Qutub Minar complex .

Alai Darwaza was built by Alauddin Khalji, the Sultan of Delhi (1296-1316), around 1311 AD.
It is the part of Alauddin's ambitious plan to expand the pre-existing Quwwat-ul-Islam Mosque on all four sides.
However, due to the Sultan's death in 1316, only the Alai Darwaza was completed, making it the southern gateway to the mosque complex.