KASI, Jaintia, Naga, and Mizo hills together form the Purvanchal range.The MENTIONED hills like Garo, Khasi COVERS the Shillong plateau of Meghalaya.The Purvanchal range mainly includes the Patkai, Barail, Manipur, Mizoram, and Naga Hills hills.Hence, option 3 is correct.In the easternmost parts of Indian country, the Purvanchal Range is the EXTENSION of the Himalayas.The sedimentary rock consists of most of these mountains.The main feature of these ranges is it is covered by dense forests.This range runs across Arunachal Pradesh, Nagaland, Manipur, and Mizoram states.Jaintia hills are located in the EASTERN part of Meghalaya. Naga hills are situated on the border of India and Myanmar.