Which of the following may be considered as a primary source for understanding…

A primary source is direct, first-hand evidence created during the very period being studied — an object, inscription, painting, or physical remain dating to that era itself, as distinct from a later secondary account written or painted about it afterward. Since prehistoric humans left no written records, only physical remains from that period — tools and rock art they made, or skeletal and fossil remains they left behind — can serve as primary sources for it.

Rock-shelter sites such as Bhimbetka in Madhya Pradesh preserve paintings ranging from the Mesolithic period, with some even earlier Upper Paleolithic elements, through later historical times. Their oldest layers were painted directly by early hunter-gatherers on the cave and rock-shelter walls, depicting hunting scenes, animals, and daily activities exactly as those early humans lived them — making them a genuine primary source for studying early human life in India.

Cross-check — why the other options are not prehistoric primary sources:

• Kangra style painting: an 18th-century Pahari miniature art tradition depicting courtly and romantic themes — many millennia after early humans, so it documents a later historical culture, not the prehistoric period.

• Girnar rock inscription: a Mauryan-era edict of the 3rd century BCE — historical India, far removed from the era of early humans.

• Padshahnama painting: a 17th-century Mughal manuscript illustration of court events — a historical-period artwork, not prehistoric evidence.

Only the rock paintings of Madhya Pradesh originate from the prehistoric period itself, created by early humans directly, which is why they are the primary source among the given options.