The correct answer is: a) Directorate of Mines and Geology.
The Directorate of Mines and Geology is a government agency responsible for the management of mineral resources in Sikkim. It is responsible for granting mining leases, issuing mining permits, and monitoring mining activities.
The Sikkim State Pollution Control Board is a government agency responsible for the prevention and control of pollution in Sikkim. It is not responsible for granting mining leases.
The Ministry of Environment and Forests is a government ministry responsible for the management of the environment and forests in India. It is not responsible for granting mining leases in Sikkim.
Local village councils are not responsible for granting mining leases in Sikkim.