Andhra Pradesh Eastern Power Distribution Company Limited (APEPDCL) and Andhra Pradesh Southern Power Distribution Company Limited (APSPDCL) are the main:

The correct answer is: b) Electricity distribution companies.

APEPDCL and APSPDCL are the main electricity distribution companies in Andhra Pradesh. They are responsible for the transmission and distribution of electricity to consumers in the state.

Power generation companies are responsible for the generation of electricity. Regulatory bodies are responsible for regulating the electricity sector. Renewable energy developers are responsible for the development of renewable energy projects.