The correct option is D
Patkai hills, the Manipur hills, the Mizo hills
Explanation:
Passing from Arunachal Pradesh, there is an eastward extension of the Himalayas in the north- eastern region of India. This is known as Purvanchal Hills. Purvanchal Hills comprises the Patkai hills, the Manipur hills, Bairal range, the Mizo hills and the Naga hills. It is a densely forested area, mainly composed of strong sandstones.
Note: The Eastern Himalayas occupy Arunachal Pradesh and Bhutan. The important hills in this region are Aka Hills, Dafla Hills, Miri Hills, Mishmi Hills, Namcha Barwa. The Dihang and Debang passes of Arunachal Pradesh are its parts.