What Does Ego Stand for in a Depiction of a Kinship

What does ego stand for in a depiction of a kinship system?

A) the sense of distinct individuality that is present in any society
B) the emotional attachment felt by the people who use the system
C) the point of reference used to determine which kin terms go where
D) the boundary between one's kin group and outsiders
E) a gender-free way of reckoning kinship