In a tribal area, land long used in common came to be held as plots o…

The correct answer is Option (4) → Their community-based forms of collective ownership were placed at a disadvantage

Option (1) Stratification among them gave rise to new ruling kingdoms — Incorrect. Stratification among adivasi communities gave rise to kingdoms, such as many so-called Rajput kingdoms of central and western India. That came from ranking inside the communities, and private property in land played no part in it.

Option (2) They came to define themselves as tribals against newly met others — Incorrect. Tribals began to define themselves as tribals after contact with pre-existing states and newly met others. This ideology of tribalism grows out of that contact, and a change in land ownership does not cause it.

Option (3) They were absorbed into the Shudra fold of caste Hindu society — Incorrect. Acceptance into the Shudra fold followed conquest by caste Hindus. It is one way tribes were absorbed into Hindu society, and it does not follow from land becoming private property.

Option (4) Their community-based forms of collective ownership were placed at a disadvantage — Correct. Private property means land owned and sold by individuals. Its coming adversely affected tribals, because their community-based forms of collective ownership were placed at a disadvantage.