The Patkai Hills form a natural border between Assam and which state?

Manipur
Tripura
Arunachal Pradesh
Nagaland

The correct answer is (c) Arunachal Pradesh.

The Patkai Hills are a mountain range in northeastern India that form a natural border between Assam and Arunachal Pradesh. The hills are part of the Eastern Himalayas and are home to a variety of plant and animal life. The Patkai Hills are also an important watershed, providing water for the Brahmaputra River and its tributaries.

Manipur is a state in northeastern India that is located to the south of the Patkai Hills. Tripura is a state in northeastern India that is located to the west of the Patkai Hills. Nagaland is a state in northeastern India that is located to the north of the Patkai Hills.