TANGEDCO (Tamil Nadu Generation and Distribution Corporation) is the primary:

TANGEDCO (Tamil Nadu Generation and Distribution Corporation) is the primary electricity utility in the state of Tamil Nadu, India. It is a state-owned company that was formed in 1998 by the merger of the Tamil Nadu Electricity Board and the Tamil Nadu Generation and Distribution Corporation. TANGEDCO is responsible for the generation, transmission, and distribution of electricity in Tamil Nadu. It has a total installed capacity of over 15,000 MW and serves over 20 million consumers.

The other options are incorrect because:

• Option (b), Coal mining company, is incorrect because TANGEDCO does not mine coal. It purchases coal from other companies to generate electricity.
• Option (c), Renewable energy developer, is incorrect because TANGEDCO does not develop renewable energy projects. It purchases renewable energy from other companies.
• Option (d), Water resources management agency, is incorrect because TANGEDCO is not responsible for managing water resources. This is the responsibility of the Tamil Nadu Water Resources Department.