The correct answer is (a) year 1978.
The Directorate of Environment was organized in India in 1978. It is a part of the Ministry of Environment, Forest and Climate Change. The Directorate is responsible for implementing the environmental laws and policies of the Government of India. It also conducts research on environmental issues and provides technical assistance to the states and Union Territories.
The other options are incorrect. Option (b) is incorrect because the Directorate of Environment was organized in 1978, not 1977. Option (c) is incorrect because the Directorate of Environment was organized in 1978, not 1979. Option (d) is incorrect because the Directorate of Environment was organized in 1978, not 1976.