The traditional administrative unit comprising of a group of villages in Arunachal Pradesh is the:

The correct answer is: d) Gram Panchayat.

A Gram Panchayat is a traditional administrative unit comprising of a group of villages in Arunachal Pradesh. It is the lowest level of government in the state and is responsible for providing basic services to the people. The Gram Panchayat is headed by a Sarpanch, who is elected by the people of the village.

The other options are incorrect because:

• A Zilla Parishad is a district-level local government body in India.
• A Circle is a sub-district administrative unit in India.
• A Mandal is a revenue division in India.

I hope this helps! Let me know if you have any other questions.