The correct answer is A. Hisar.
Hisar is a city in the Indian state of Haryana. It is the headquarters of Hisar district and Hisar division. The city is located in the northern part of the state, on the banks of the Saraswati River. Hisar is a major agricultural and industrial center. It is also home to a number of educational institutions, including the University of Hisar.
The city is known as the “Cotton City” of Haryana because it is a major producer of cotton. The cotton industry is the backbone of the city’s economy. The city is also home to a number of cotton mills and textile factories.
The other options are incorrect because they are not known as the “Cotton City” of Haryana. Rewari is known as the “City of Lakes”. Jhajjar is known as the “City of Temples”. Palwal is known as the “City of Gardens”.