Explanation:

- Matrifocality: This is when women, especially mothers, are central figures in a family. Authority and daily life focus around them.

- Matriarchy: This refers to a society where women hold power and leadership roles, not just in families but in political and social life too.

- Matrilocality: In this system, when a couple marries, the husband moves to live with the wife’s family.

- Matrilineality: Here, lineage and inheritance pass through the mother's side. Children belong to the mother's family line.

The Nair community is known for matrilineality, where property and family identity are traced through women.

Correct Answer: Option 4 - Matrilineality