The correct answer is B. 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 custodian of India’s foreign exchange reserves, and the lender of last resort to the banking system. It also regulates the country’s monetary policy and financial system.
The Central Bank of India (CBI) is a private sector bank in India. It was founded in 1911 by a group of Indian businessmen and industrialists. The CBI is headquartered in Mumbai.
The State Bank of India (SBI) is a state-owned banking and financial services company in India. It is the largest commercial bank in India and the largest employer in the country. The SBI is headquartered in Mumbai.
The Punjab National Bank (PNB) is a state-owned banking and financial services company in India. It is the second largest commercial bank in India after the State Bank of India. The PNB is headquartered in New Delhi.
Therefore, the central banking functions in India are performed by the Reserve Bank of India only.