The correct answer is: a) Hydropower generation.
Arunachal Pradesh has a huge potential for hydropower generation. The state has an estimated hydropower potential of 50,000 MW, of which only about 2,000 MW has been harnessed so far. The state government has set a target of generating 10,000 MW of hydropower by 2020.
Hydropower is a clean and renewable source of energy. It has the potential to provide a significant boost to the economy of Arunachal Pradesh. The development of hydropower projects would create employment opportunities, generate revenue for the state government, and improve the quality of life of the people of the state.
The other options are not as feasible for economic growth in Arunachal Pradesh. Mining is a polluting industry and it would have a negative impact on the environment of the state. Large-scale manufacturing is not possible in Arunachal Pradesh due to the lack of infrastructure and skilled manpower. Offshore oil exploration is also not a feasible option as the state does not have any offshore oil reserves.
In conclusion, hydropower generation is the most potential area for economic growth in Arunachal Pradesh. It is a clean and renewable source of energy that has the potential to provide a significant boost to the economy of the state.