The correct answer is A. Hisar.
Manganese is a chemical element with the symbol Mn and atomic number 25. It is a metal that is found in nature in the form of manganese ore. Manganese is used in a variety of industries, including steelmaking, battery production, and fertilizer production.
The manganese ore deposits in Hisar district are among the largest in India. The ore is mined and then processed to produce manganese metal. The manganese metal is then used in a variety of industries.
The other options are incorrect. Mahendragarh district is not known for its manganese deposits. Karnal district is known for its production of rice and wheat. Gurugram district is a major financial and technology hub.