Which of the following is LEAST likely to result in the ULP of employers? a) An employer transfers an employee who filed a charge with the National Labor Relations Board or gave testimony before the National Labor Relations Board. b) An employer shares factual information about other firms that had to close their plants because of the labor conflict with unions. c) An employer prohibits employees from talking about unions during working hours. d) An employer implies a promise of benefits whether or not the union is organized