The correct answer is D. RBI.
The Reserve Bank of India (RBI) is the central bank of India. It was established on April 1, 1935, in accordance with the Reserve Bank of India Act, 1934. The RBI is the banker to the Government of India, the banker’s bank, and the lender of last resort to the banking system. It also regulates the Indian financial system.
The MRTP Act, 1969, is an act to provide for the regulation of monopolies and restrictive trade practices. The FERA, 1973, is an act to regulate foreign exchange and to provide for matters connected therewith. The Factories Act, 1948, is an act to regulate the conditions of work in factories.
All of these acts are related to the legal environment of business in India. The RBI, on the other hand, is not directly related to the legal environment of business. It is a regulatory body that oversees the Indian financial system.