The correct answer is (a) SEBI.
SEBI, or the Securities and Exchange Board of India, is the regulator of the securities market in India. It was established in 1992 by the Government of India to protect the interests of investors in securities and to promote the development of the securities market. SEBI regulates all aspects of the securities market, including mutual funds.
The National Stock Exchange (NSE) is a stock exchange in India. It is the largest stock exchange in India by market capitalization. The NSE was established in 1992 and is headquartered in Mumbai.
The Reserve Bank of India (RBI) is the central bank of India. It was established in 1935 and is headquartered in Mumbai. The RBI is responsible for the regulation of the banking sector in India.
The Indian Bank Association (IBA) is the apex body of scheduled commercial banks in India. It was established in 1946 and is headquartered in Mumbai. The IBA represents the interests of its members to the government and other regulatory bodies.
SEBI is the correct answer because it is the regulator of the securities market in India. The NSE, RBI, and IBA are not regulators of the securities market.