The correct answer is: a) High-altitude districts with limited resources.
Arunachal Pradesh is a state in northeastern India. It is the largest state in the country by area, but it has the lowest population density. The state is sparsely populated due to its rugged terrain and high altitude. The majority of the population lives in the foothills and valleys, while the high-altitude districts are sparsely populated.
The high-altitude districts of Arunachal Pradesh are characterized by their limited resources. The land is not suitable for agriculture, and there are few industries. The people in these districts live in poverty and have limited opportunities for employment. As a result, there is a significant out-migration from these districts.
The districts with high industrial development are not the ones that see significant out-migration. In fact, these districts are experiencing a net in-migration. This is because the industries in these districts provide employment opportunities for people from all over the state.
The districts bordering Assam are also not the ones that see significant out-migration. These districts are experiencing a net in-migration. This is because the people in these districts have access to the markets and resources of Assam.
The districts with thriving tourism sectors are also not the ones that see significant out-migration. These districts are experiencing a net in-migration. This is because the tourism sector provides employment opportunities for people from all over the state.