Correct Answer:
D. Jehlum
The correct answer is Jehlum. Nandana Fort is a historical fort situated in the district of Jehlum (also spelled Jhelum) in Punjab, Pakistan. It was originally built by the Hindu Shahi dynasty and later captured by Mahmud of Ghazni. Notably, the great scholar Al-Biruni used this site for his calculations of the Earth's circumference.
- Islamabad: The capital city, with no association with this fort.
- Lahore: A major city, but the fort is not located there.
- Rawalpindi: A nearby city, but not the location of Nandana Fort.
Therefore, the correct answer is Jehlum.