The Securities and Exchange Board of India (SEBI) is the regulatory authority for the securities market in India. Its functions include protecting investors, promoting the development of the securities market, and regulating market intermediaries and instruments. Options A, B, and D (regulating venture capital funds, collective investment schemes, and mutual funds) fall under the purview of SEBI as these are investment vehicles operating in the securities market. The regulation of insurance policies and companies falls under the Insurance Regulatory and Development Authority of India (IRDAI).