Which of the following is NOT one of the 3 characteristic forms of a "common bond" requirement?

Occupational - 80% of the members share the same employer or industry.

Associational - 80% of its members are of the same religion, trade association, or trade union.

Residential - 80% of its members live in a qualified sparsely populated rural county or low income area.

Political Affiliation - 80% of its members are of the same political party.