M'ore Mining Company's employees want a union to represent their rights. All of the employees live in company-owned employee housing adjacent to their place of work. In order for a union to be established, solicitation must be carried out by pro-union employees. Which of the following rules may assist those employees in their union solicitation efforts on M'ore Mining property?

a. the imcompatibility caveat

b; the incontestability exclusion

c. the inaccessibiltiy exception

d. the insubordination proviso