The question describes a specific type of marriage system involving two distinct groups, Group A and Group B.
This describes a direct, symmetrical, and reciprocal exchange between only two groups. This specific form of marriage alliance is known as restricted exchange.
Restricted exchange refers to a marriage system where alliances are formed strictly between two specific social groups or categories. The exchange is direct and balanced, with each group giving spouses to the other.
This contrasts with other forms like generalized exchange, which typically involves more than two groups in a cyclical pattern.
Therefore, the scenario presented is a classic example of restricted exchange.
Patriliny is a kinship term that refers to_________.