Answer: C. Unilineality
Explanation: Unilineality is a system of determining descendant group in which one belongs to either the male (patriline) or female(matriline) both not both. Both patrilineal and matrilineal system are both examples of a unilineal system.
Ambilineal are non-unilineal where individual can be affiliated to more than one genealogical line.
Cosanguinity refers to being of the same descent with another individual.