The correct answer is option 'C': Arunachal Pradesh.

Explanation:
Arunachal Pradesh is a state in Northeast India, known for its rich cultural diversity and numerous tribal communities. One of the prominent tribes in Arunachal Pradesh is the Dafla tribe.

The Dafla tribe primarily resides in the Lower Subansiri district of Arunachal Pradesh. They are one of the major tribal communities in the state and have a distinct culture, language, and traditions.

Here is some additional information about the Dafla tribe:

1. Location:
- The Dafla tribe is mainly concentrated in the Lower Subansiri district, which is located in the western part of Arunachal Pradesh.
- The district shares its borders with Assam and is surrounded by the Kameng and Upper Subansiri districts of Arunachal Pradesh.

2. Culture and Traditions:
- The Dafla tribe has a rich cultural heritage, and their traditional customs and rituals are an integral part of their daily life.
- They have their own unique language, called Dafla, which belongs to the Tibeto-Burman language family.
- Agriculture is the primary occupation of the Dafla people. They cultivate crops like rice, millets, and vegetables.
- They also practice hunting and fishing as supplementary means of livelihood.

3. Festivals:
- The Dafla tribe celebrates several festivals throughout the year. One of the most important festivals is the Nyokum festival, which is dedicated to the goddess of wealth and prosperity.
- During the festival, various rituals, cultural performances, and traditional games are organized to celebrate the harvest season.

4. Traditional Attire:
- The traditional attire of the Dafla tribe includes colorful woven garments, bead necklaces, and bamboo accessories.
- Men usually wear sleeveless jackets, long shirts, and trousers, while women wear blouses, skirts, and shawls.

In conclusion, the Dafla tribe can be found in Arunachal Pradesh, specifically in the Lower Subansiri district. They have a distinct culture, language, and traditions that are deeply rooted in their daily lives.