The correct answer is: Rohtak and Karnal districts.
A zamindari was a large landholding estate in British India, held by a zamindar, or landlord. The zamindars were responsible for collecting taxes from the peasants who worked on their land.
The zamindari system was abolished in India in 1952, but its legacy continues to be felt in Haryana. The districts of Rohtak and Karnal are home to some of the largest zamindari estates in the state. These estates are often controlled by powerful families who have held them for generations.
The zamindari system has had a significant impact on the social and economic development of Haryana. The zamindars have traditionally been a powerful and influential group, and they have often used their power to exploit the peasants who work on their land. This has led to a great deal of inequality in Haryana, and it has also made it difficult for the state to develop.
In recent years, there have been a number of efforts to reform the zamindari system in Haryana. These efforts have met with some success, but the system is still a major obstacle to development in the state.
The other options are incorrect because they do not have a concentration of large zamindari estates. Ambala and Hisar districts are home to a number of small and medium-sized landholdings, while Gurgaon and Faridabad districts are primarily urban areas. Panipat and Sonipat districts are also home to a number of small and medium-sized landholdings, but they do not have the same concentration of large zamindari estates as Rohtak and Karnal districts.