Karbi Anglong Plateau is an extension of

Concept: The Peninsular Plateau is one of the oldest and most stable landmasses of India, built of ancient crystalline, igneous, and metamorphic rock (gneiss and schist).

Application: The Karbi Anglong Plateau, lying south of the Brahmaputra valley in Assam alongside the Meghalaya Plateau and North Cachar Hills, is made of this same ancient crystalline rock. It is separated from the Chotanagpur Plateau (the main Peninsular block) by the Malda Fault, and the resulting depression has since been filled by alluvium deposited by rivers flowing towards the Ganga-Brahmaputra plains -- so it is classified as the Peninsular Plateau's northeastern extension.

Cross-check -- why the other options don't fit:

• Tibet is a high plateau raised through continental collision and crustal thickening during the India-Eurasia convergence -- a fundamentally different tectonic origin from the stable, fault-bounded continuity that links Karbi Anglong to the Peninsular block.

• The Himalaya are young fold mountains of folded sedimentary strata thrown up in the same collision, not a stable ancient crystalline block.

• The Shan Plateau lies within Myanmar's own separate Southeast Asian tectonic block, unconnected to the Indian Peninsular landmass.