Explanation:

- Option 1: Nuclear

- Refers to a family structure with two parents and their children.

- Common in urban settings worldwide, but not specific to Khasis.

- Option 2: Conjugal

- Focuses on the marital relationship and the immediate family.

- It overlaps with nuclear family dynamics.

- Option 3: Patriarchal

- A family system where the father or eldest male is the head.

- Typical in many cultures but not characteristic of the Khasis.

- Option 4: Matriarchal

- Society where women, especially mothers, hold central roles of leadership.

- The Khasis, known for their matrilineal tradition, inherit from the mother’s side and trace lineage through women.