Districts in Arunachal Pradesh serve as important units for:

The correct answer is: d) All of the above

Districts in Arunachal Pradesh serve as important units for the delivery of public services, revenue collection, and implementation of development schemes.

• Delivery of public services: Districts are the basic units of administration in India, and they are responsible for the delivery of a wide range of public services, including education, healthcare, and infrastructure. In Arunachal Pradesh, districts are also responsible for the delivery of social welfare schemes and the implementation of government programs.
• Revenue collection: Districts are also responsible for collecting revenue from taxes and other sources. This revenue is used to fund the delivery of public services and the implementation of development schemes.
• Implementation of development schemes: Districts are also responsible for the implementation of development schemes. These schemes are designed to improve the lives of people living in the district, and they cover a wide range of areas, such as agriculture, education, health, and infrastructure.

The role of districts in Arunachal Pradesh is important, and they play a vital role in the development of the state.