51) Which of the following is an example of a union unfair labor practice? A) Sam, a union member, is threatened by Rashida, his boss, with loss of benets if he votes for a umon. B) Graciela, an operations head, threatens to close down a plant if organized by a union. C) Lillian, a HEW employee, refuses to join a union. D) Hill, a nonunion employee, spies on union meetings. E) Nestor, a union representative, makes a contract that requires his employer to hire employees satisfactory to the union