The correct answer is (a) ECGC.
The Export Credit Guarantee Corporation of India (ECGC) is a government-owned corporation that provides export credit insurance and guarantees to Indian exporters. It was established in 1957 to promote Indian exports by providing financial assistance to exporters and by mitigating the risks associated with international trade.
GAIL (India) Limited is a state-owned natural gas company that is engaged in the exploration, production, transportation, and marketing of natural gas. It was established in 1984 as a joint venture between the Government of India and the Government of the United States.
The Central Board of Direct Taxes (CBDT) is the apex direct tax policy-making body in India. It is responsible for formulating and administering the direct tax laws in India.
The Industrial Development Bank of India (IDBI) is a state-owned development bank that is engaged in financing industrial projects. It was established in 1964 with the objective of promoting industrial development in India.
ECGC is the only institution among the given options that is related to export financing and insurance. It provides financial assistance to exporters and mitigates the risks associated with international trade.