(a) The individuals eligible for insurance under the policy are:
(1) all employees of the employers and the employees of the trade association of those employers;
(2) all members of the labor union; or
(3) all of any class or classes of employees or members determined by conditions relating to their employment, to their membership in the unions, or both.
(b) A director of a corporate employer is not eligible for insurance under the policy unless the person is otherwise eligible as a bona fide employee of the corporation by performing services other than the usual duties of a director.
(c) An individual proprietor or partner is not eligible for insurance under the policy unless the person is actively engaged in and devotes a substantial part of the person's time to conducting the business of the proprietorship or partnership.