Which district has been declared as the 22nd district of Haryana?

The correct answer is A. Nuh.

Nuh was declared as the 22nd district of Haryana on 26 January 2022. It was carved out of the Gurgaon district. The district has a population of over 1.5 million people and is spread over an area of 2,300 square kilometers. The headquarters of the district is located at Nuh town.

The other options are incorrect. Charkhi-Dahri is a district in Haryana that was formed in 2005. Palwal is a district in Haryana that was formed in 1979.