The correct answer is option 2: Peninsular plateau.

The peninsular plateau in India is characterized by rigid and stable elevated lands, denuded rocks, and a series of scarps.

The peninsular plateau covers a large part of central and southern India. It is an ancient and stable landmass, composed mainly of hard and resistant rocks such as granite, gneiss, and basalt. Over millions of years, weathering and erosion have resulted in the denudation of the plateau, exposing the bare rocks and creating a rugged landscape.

The plateau is also marked by a series of steep slopes or scarps, formed due to the differential erosion of rocks. These scarps give the plateau a distinctive appearance and contribute to its rugged terrain.

It is important to note that the other options are incorrect. The northern mountains, option 1, are characterized by young fold mountains like the Himalayas, while the northern plains, option 3, are low-lying and flat plains formed by the deposition of sediments. The coastal plains, option 4, are narrow stretches of flat land along the coastlines.