Martha Was Very Concerned for Her Organization

Martha was very concerned for her organization. Her employer had always expressed its preference to have a non-unionized workforce. As the Director of the HR department, she had started noticing some odd behaviour and thought she recognized a local union organizer in the parking lot of the company during lunch break. In addition, she had been recently receiving a lot more requests for information on compensation and benefits from employees than usual. She was particularly concerned went she went for coffee with her long time friend and colleague in the marketing area, and her friend wouldn't give her a clear answer when she asked if there was anything new or interesting happening at the workplace. As it was her job to know what was happening in her workplace amongst employees, and to ensure that salaries and working conditions were competitive, she wondered what she should do now.
-Once a union drive is underway,Martha,who would represent management

A) may not discipline employees for supporting the union.
B) may not discipline employees for supporting the union,except for those who are actively organizing.
C) may not discipline employees for supporting the union,but may legally charge outside union organizers.
D) may not discipline employees,but can warn them of serious negative ramifications if they organize.
E) may discipline employees for supporting the union,though may not dismiss them without warnings.