Regarding representation election procedures, which of the following statements is true? a. at least 50% of the employees in a bargaining unit must sign authorization cards b. an employer may recognize a union only if at least 50% of the employees in a bargaining unit have signed authorization cards c. if an election is ordered, the employer must provide to the union names and addresses of employees within 7 days d. the time between when an election is ordered and when it takes place is the time of least scrutiny of the activities of the employer and the union