Answer: (Detailed Solution Below)
Option B: Khiri and Sant Ravi Das Nagar
Detailed Solution:
The correct answer is “Khiri and Sant Ravi Das Nagar”.
The largest district in Uttar Pradesh by area is Lakhimpur Kheri, covering 7,680 square kilometers. The smallest district in Uttar Pradesh by area is Hapur, covering 660 square kilometers.
As per the 2011 census, Bhadohi district is the smallest district in Uttar Pradesh state. It is also referred to as Sant Ravidas Nagar.